Treatment & Care

"Unfortunately, gemstones don't come out of the ground ready to be set in jewelry.

Raw crystals from the earth are usually called rough gemstones (or just rough)

and this is actually very apt - rough gems can look pretty rough!"

To make sure each gemstone reaches its full potential, lapidaries and jewelers employ a variety of techniques. Some of these, like cutting and setting, are immediately visible, while others such as enhancements or treatments remain relatively unknown, despite being used for thousands of years. Practiced in India for over 4,000 years, the earliest known gemstone enhancement is heating a gem to improve its color. Oiling to improve a gem’s clarity is another ancient technique that has been used for over 2,000 years. Not all gemstone enhancements can trace their origins to antiquity. Some, such as the physical vapor deposition (PVD) of Mystic Topaz, are the result of more recent innovations.

Examples of the Opal family

Examples of the Opal family

In the gem industry, the term ‘enhancements’ sometimes exclusively refers to traditional techniques that are so common they are seldom mentioned. The term ‘treatment’ is reserved for more modern methods. The problem is that this is not universal - both terms are often used to refer to the same processes.

Regardless of what they are called, all gemstone enhancements simply accentuate the beautiful end results of gemstones’ natural formation. With the vast majority of gems enhanced in some way, these processes have become an important part of the modern gemstone industry. However, to be sure you have obtained a truly untreated gemstone, you must ensure you have a gem that has been certified as ‘natural’. A ‘natural’ gemstone is one that has not been enhanced or treated in any way.

Enhancement Disclosure

The World Jewelery Confederation (CIBJO or Confédération Internationale de la Bijouterie, Joaillerie, Orfèvrerie, des Diamants, Perles et Pierres) is the organization that records accepted trade practices and nomenclature for the global gem and jewelery industry.

Under their guidelines, all jewelers should be aware of how the gems they sell are enhanced, disclosing this information to their customers. Today, many gemstone enhancements are very difficult to detect without the use of specialized equipment.

Marvelous Tourmaline

Marvelous Tourmaline

Gem Care Do’s & Don’ts

Gemstone enhancements can make gemstones more beautiful, affordable and even more durable. Despite this, some gems require special care. This section includes some simple gem grooming tips for the maintenance of your jewels. The following tables show acceptable enhancements applied to each gem variety, their frequency and final effect. They also display any relevant special care instructions.

What to do...

  • Do keep your gemstone jewelry in the separate compartments of a jewelery box or in cloth pouches, always storing your gem necklaces flat.
  • Do gently wipe your jewelry with a lint-free cloth after each wearing to remove oils and salts.
  • Do periodically clean your jewelry. Rings can easily collect dust, soap and grime behind the setting if you wear them regularly. While a dirty gem will lose color and brilliance, most gemstones are easily cleaned by soaking them in water with a little gentle soap. If especially dirty, use a very soft toothbrush to gently scrub behind the gem. Organic gems like Pearls or Amber should only be wiped clean with a moist cloth.
  • What not to do...

  • Don’t put on your jewelry before using cosmetics, hair spray or perfumes. Some gemstones are porous and may absorb chemicals that can discolor them.
  • Don’t ever remove your jewelry by pulling on the gems as this can loosen their settings, resulting in them falling out.
  • Don’t ever store your jewelry in heaps as your gems can scratch each other. As almost every gemstone is harder than gold, silver or platinum, even the finish of your jewelry can be damaged if you do so.
  • Don’t wear your jewelry when playing sports, doing housework or anything else that risks damaging them.
  • Don’t use a commercial cleaning solution until you have checked it is suitable for your gem.
  • Don’t use ultrasonic or steam cleaners for every gem. Most importantly, exercise common sense: if you are not sure, avoid using unusual technique for polishing and cleaning your jewels.

Agate (Blue Banded Agate, Botswana-Achat, Dendritic Agate, Glitter Agate, Moss Agate, Green Agate, Fire Agate)

Enhancement None Explanation Without explanation Care for Keep away from heat and drying environments Steam cleaning no Ultrasonic cleaning no

Actinolite (Cats Eye Actinolite)

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Alexandrite (Alexandrite, Brazilian Alexandrite, Russian Alexandrite, Cats Eye Alexandrite, Cats Eye Brazilian Alexandrite)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Amazonite

Enhancement Colourless oil or wax, paraffin or hardened resin and/or impregnated with colourless plastic or hardened resin Explanation Colourless oil and wax are usually applied, impregnation with colourless plastic or hardened resin is occasional. All improve appearance. Care for None Steam cleaning yes Ultrasonic cleaning no

Amblygonite

Enhancement None Explanation Without explanation Care for Some gemstones can be damaged by thermal shock, do not expose to extreme temperature changes. Steam cleaning no Ultrasonic cleaning no

Amethyst (Rose de France Amethyst, Multicolour Amethyst, Platina Amethyst, Sunset Amethyst)

Enhancement Heated Explanation Occasionally used to lighten colour and/or remove smokiness Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions! Steam cleaning yes Ultrasonic cleaning no

Amethyst (Green Amethyst, Rio Grande Green Amethyst)

Enhancement Irradiated and/or heated Explanation Usually applied to improve/provide colour. Care for None Steam cleaning yes Ultrasonic cleaning no

Amethyst (Brejinho Amethyst, Zambian Amethyst, Uruguayan Amethyst, AAA Amethyst, Bolivian Amethyst, Nigerian Amethyst, Sibirian Amethyst)

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Ametrine (Ametrine, Kaleidoscope Ametrine)

Enhancement Heated Explanation Rarely used to improve colour. Care for None Steam cleaning yes Ultrasonic cleaning no

Ammolith

Enhancement Keine Explanation Specially polished to improve colour. Care for Very fragile, handle with care! Steam cleaning no Ultrasonic cleaning no

Andalusite

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Andesine (Red Andesin, Green Andesine)

Enhancement Heated or/and diffused by using copper Explanation Occasionally used to improve or produce colour. Care for None Steam cleaning yes Ultrasonic cleaning no

Angelite

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Anglesit

Enhancement None Explanation Without explanation Care for Very fragile, handle with care! Steam cleaning no Ultrasonic cleaning no

Apatite (Apatite, Diego Suarez Apatite, Caribbean Blue Apatite, Ultramarine Apatite, Neon Blue Apatite, Porto Madeira Apatite)

Enhancement Heated Explanation Used in order to improve the appearance and/or intensify colour. Care for None Steam cleaning no Ultrasonic cleaning no

Apatite (Chrome Apatite, Green Fluorapatite, Canadian Apatite, Lemon Apatite, Russian Apatite, Xia Apatite)

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Aquamarine (Aquamarine, AAA Aquamarine, Bauchi Aquamarine, Boca Rica Aquamarine, Santa Maria Aquamarine, Santa Teresa Aquamarine, Sao Domingos Aquamarine, Pedra Azul Aquamarine, Tatu-Aquamarin)

Enhancement Heated Explanation Usually applied to remove yellow or green components to produce a pure blue colour. Care for None Steam cleaning yes Ultrasonic cleaning no

Aquamarine (Cats Eye Aquamarine)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Aragonite (Capillitas Aragonite)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Aventurine

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Axinit

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Azurit

Enhancement Surface colourless waxing and/or impregnation with colourless plastic or hardened resin. Explanation Impregnation is rarely used, waxing is commonly used. All improve stability, durability, lustre and/or colour. Care for None Steam cleaning yes Ultrasonic cleaning no

Benitoit

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Amber

Enhancement Heated Explanation Heating is usually applied to improve appearance and/or colour intensity. Care for Clean by gently wiping with a moist cloth Steam cleaning no Ultrasonic cleaning no

Beryl (Beryl, Amazon Beryl, Himalaya Beryl, Imperial Beryl, Lagoon Beryl, Red Beryl, Cats eye Red Beryl)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Beryl (Yellow Beryl)

Enhancement Heated or irradiated Explanation Usually applied to improve/provide colour. Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions! Steam cleaning yes Ultrasonic cleaning yes

Beryl (Bixbit)

Enhancement colourless oil and resin Explanation Commonly used to improve appearance Care for None Steam cleaning no Ultrasonic cleaning no

Bronzite

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Chalcedony (Angelite, Green Chalzedony, Flintstone)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Chalcedony (Pink Chalzedony)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Chiastolith

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Chondrodite

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Chrysoberyl (Chrysoberyl, Cats Eye Chrysoberyl, Tunduru Chrysoberyl)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Chrysokoll

Enhancement Surface colourless waxing and/or impregnation with colourless plastic or hardened resin. Explanation Occasionally used to improve appearance. Care for None Steam cleaning no Ultrasonic cleaning no

Chrysoprase (Chrysoprase, Imperial Chrysoprase)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Cinnabarit

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Citrine (AAA Citrin, Madeira Citrine, Mandarin Citrine)

Enhancement Heated Explanation Usually applied to provide colour. Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions! Steam cleaning yes Ultrasonic cleaning no

Citrine (Multicolour Citrine, Lemon Citrine)

Enhancement Heated or irradiated Explanation Usually applied to provide colour. Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions! Steam cleaning yes Ultrasonic cleaning no

Danburite

Enhancement Irradiated Explanation Commonly used to improve appearance Care for None Steam cleaning no Ultrasonic cleaning no

Danburite (Neon Yellow Danburite, Cats Eye Danburite)

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Danburite (White Danburite, Pink Danburite)

Enhancement None Explanation Commonly used to improve appearance Care for None Steam cleaning no Ultrasonic cleaning no

Tektit (Demantoid, Ambanja-Demantoid, Namibia-Demantoid)

Enhancement None Explanation Without explanation Care for Some gemstones can be damaged by thermal shock, do not expose to extreme temperature changes. Steam cleaning no Ultrasonic cleaning no

Diamond (VVS2 Blue Diamond, Champagne Diamond, SI Cognac Diamond, Yellow Diamond, Yellow SI1 Diamond, VS1 Diamond, Green Diamond, VS1 Orange Diamond, VS2 Orange Diamond, Pink Diamond, SI Pink Diamond, SI1 Pink Diamond, Red Diamond, SI Red Diamond, Black Diamond)

Enhancement Irradiated and/or heated Explanation Used to improve colour intensity or to produce unique colours. Care for Keine Steam cleaning yes Ultrasonic cleaning yes

Diamond (VVS Diamond, Argyle Champagne Diamond, VVS Argyle Champagne Diamond, Argyle Fancy Diamond, SI Argyle Fancy Diamond, VS Argyle Fancy Diamond, VVS Argyle Fancy Diamond, Argyle Champagne Diamond, VS Argyle Champagne Diamond, VS1 (E) Diamond, VS1 (F) Diamond, VS2 (D) Diamond, IF (D) Diamond, VS1 (G) Diamond, VS1 (H) Diamond, VS2 (F) Diamond, VVS1 (E) Diamond, VVS2 (E) Diamond, VS1 (D) Diamond, VVS1 (G) Diamond, VVS2 (D) Diamond)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Diopside (Russian Diopside)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Dumortierite

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Epidot

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Eudialyt

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Anglesit (Hawk's Eye)

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Fluorite (Mint Fluorite, Rose Fluorite)

Enhancement Irradiated Explanation Commonly used to provide colour. Care for None Steam cleaning no Ultrasonic cleaning no

Fluorite (Multicolour Fluorite, Capillitas Fluorite, Cumbria Fluorite, Esperanza-Fluorit, Colour Change Fluorite, Namibian Mint Fluorite, Spanish Fluorite)

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Fossil (Crinoid-Fossil)

Enhancement None Explanation Without explanation Care for Extreme temperature changes can damage the gemstones. Steam cleaning no Ultrasonic cleaning no

Gahnit

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Goshenite (Goshenite, Cats Eye Goshenite)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Garnet (Garnet, AAA Tsavorite, AAA Spessartite, Ambanja-Demantoid, Blue Colour Change Garnet, Brasilian Rhodolite, Cuamba Garnet, Colour Change Garnet, Demantoid, Hessonit Garnet, Rasberry Rhodolite, Imperial Garnet, Kamtonga Colour Change Garnet, Malaya Garnet, Merelani Mint Garnet, Mozambique Garnet, Rajasthan Rhodolite, Rhodolite, Spessartite, Star Garnet, Tangerin Garnet, Tsavorite, Cinnamon Garnet)

Enhancement None Explanation Without explanation Care for Some gemstones can be damaged by thermal shock, do not expose to extreme temperature changes. Steam cleaning no Ultrasonic cleaning no

Hematite

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Beryl (Heliodor)

Enhancement Irradiated Explanation Usually applied to improve/provide colour. Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions! Steam cleaning yes Ultrasonic cleaning yes

Heliotrop

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Hemimorphite

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Hiddenit

Enhancement Irradiated Explanation Rarely used to provide colour and colour uniformity. Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions! Steam cleaning yes Ultrasonic cleaning no

Howlite

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Idocrase (Idocrase, Vesuvianite)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Indogolith

Enhancement Natural or heated and/or irradiated Explanation Usually applied to provide/improve colour. Care for None Steam cleaning yes Ultrasonic cleaning no

Indogolith (Mutuca Indicolite, Cats Eye Mutuca Indicolite, Multicolour Mutuca Indicolite)

Enhancement Heated Explanation Usually applied to provide/improve colour. Care for None Steam cleaning yes Ultrasonic cleaning no

Iolite (Iolite, Ceylon Iolite, Orissa Iolite)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Jade (Jadeit)

Enhancement Colourless polymer impregnation and/or polymer impregnation followed by acid treatment and/or dyed. Explanation Commonly used provide colour and colour uniformity. Care for None Steam cleaning yes Ultrasonic cleaning no

Jade (Nephrit)

Enhancement Dyed and/or impregnated with colourless oil, wax or hardened resin Explanation Rarely used to provide colour and colour uniformity. Care for None Steam cleaning yes Ultrasonic cleaning no

Jade (Australian Jade, Canadian Jade)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Jasper (Dalmatian Jasper, Noreena Jasper, Peanut Jasper, Pilbara Jasper)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Jasper (Image Jasper, Leopard Jasper, Ocean Jasper, Red Jasper, Sunflower Jasper, Turtella Jasper)

Enhancement Dyed Explanation Commonly used to imitate other gemstones Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions! Steam cleaning no Ultrasonic cleaning no

Calcite

Enhancement None Explanation Without explanation Care for Very fragile, handle with care! Steam cleaning no Ultrasonic cleaning no

Carnelian

Enhancement Heated and/or dyed Explanation Dyeing is occasional, while heating is usual. All provide colour. Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions! Steam cleaning yes Ultrasonic cleaning yes

Clinohumite

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Kornerupine

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Kunzite (Canari Kunzit, Mint Kunzite, White Kunzite)

Enhancement Heated or irradiated Explanation Commonly used to improve and/or darken colour Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions! Steam cleaning yes Ultrasonic cleaning no

Kunzite (Champagne Kunzite)

Enhancement None Explanation Without explanation Care for Some stones fade when exposed to strong light. Do not unnecessarily expose gemstones to these conditions. Steam cleaning yes Ultrasonic cleaning no

Kunzite (Patroke Kunzite)

Enhancement Heated Explanation Commonly used to improve and/or darken colour Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions! Steam cleaning no Ultrasonic cleaning no

Kyanite (Kyanite, Mint Kyanite, Peacock Kyanite, Tibetian Kyanite)

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Labradorite

Enhancement Surface colourless waxing Explanation Occasionally used to improve appearance. Care for Some stones fade when exposed to strong light. Do not unnecessarily expose gemstones to these conditions. Steam cleaning no Ultrasonic cleaning no

Lapis Lazuli

Enhancement Surface colourless waxing and/or dyed Explanation Usually applied to provide colour and/or colour uniformity. Care for None Steam cleaning no Ultrasonic cleaning no

Larimar

Enhancement None Explanation Without explanation Care for Clean with a non-abrasive jewellery cleaner and one that is rated for pearls Steam cleaning no Ultrasonic cleaning no

Malachite

Enhancement Surface colourless waxing and/or impregnated with colourless plastic or hardened resin Explanation Impregnation with colourless plastic (or hardened resin) is rare, while surface colourless waxing is common and/or coating with colourless wax is occasional. All Improve colour. Care for None Steam cleaning no Ultrasonic cleaning no

Marcasite

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Mesolith

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Moldavite

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Moonstone (Moonstone, AAA Rainbow Moonstone, Ceylon Moonstone, Rainbow Moonstone, White Moonstone)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Mookite

Enhancement Heated Explanation Polishing of the gemstone after heating Care for None Steam cleaning no Ultrasonic cleaning no

Morganite (Morganite, AAA Hot Pink Morganite, Nigerian Morganite, AAA Madagascan Morganite)

Enhancement Heated or irradiated Explanation Commonly used to eliminate yellow overtones. Care for None Steam cleaning yes Ultrasonic cleaning no

Shell (Abalone Shell)

Enhancement Dyed Explanation Commonly used to improve colour. Care for Some perls fade or revert to their original colour when exposed to strong light, do not unnecessarily expose the perls to these conditions . Steam cleaning yes Ultrasonic cleaning no

Obsidian (Gold Obsidian, Mahagoni Obsidian, Snowflake Obsidian)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Onyx (Onyx, Black Onyx)

Enhancement Dyed Explanation Always used to improve colour. Care for None Steam cleaning yes Ultrasonic cleaning yes

Onyx (Stripe Onyx)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Onyx (Sardonyx)

Enhancement Dyed Explanation Usually applied to improve colour. Care for None Steam cleaning yes Ultrasonic cleaning no

Opal (AAA-Welo-Opal, Andamooka Opal, Blauer-Opal, Blue Fire Opal, Buriti Fire Opal, Boulder Opal, Coober Pedy-Opal, Eis-Opal, Fire Opal, Yellow Opal, Yellow Opal, Green Fire Opal, Semi Black Opal, Indonesischer Opal, Jelly Opal, Karibischer Opal, Lightning Ridge-Opal, Lightning Ridge Black Opal, Mexican Fire Opal, Paraiba-Opal, Mezezo-Opal, Opal-Katzenauge, Pink Opal, Salamanca-Feueropal, Black Opal, White Opal, Welo Opal, Queretaro Cherry Fire Opal)

Enhancement None Explanation Without explanation Care for Some gems can crack if they lose structural water. Keep away from heat and drying environments! Do not expose to extreme temperature changes. Steam cleaning no Ultrasonic cleaning no

Opal (Machu Picchu Opal)

Enhancement Infusion of unhardened colourless substances into voids. Explanation Occasionally used to improve appearance. Care for Some gems can crack if they lose structural water. Keep away from heat and drying environments! Do not expose to extreme temperature changes. Steam cleaning no Ultrasonic cleaning no

Opal (Matrix Opal)

Enhancement Heated with organic substances Explanation Used to improve appearance Care for Some gems can crack if they lose structural water. Keep away from heat and drying environments! Do not expose to extreme temperature changes. Steam cleaning no Ultrasonic cleaning no

Orthoklas

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Peridot (Arizona-Peridot)

Enhancement Heated and/or open fissures and cavities filled with colourless oil, wax or resin. Explanation Occasionally used to improve appearance. Care for Some gemstones can be damaged by thermal shock, do not expose to extreme temperature changes. Steam cleaning no Ultrasonic cleaning no

Peridot (Kashmir Peridot, Manchu Peridot, Zabargad-Peridot)

Enhancement None Explanation Without explanation Care for Some gemstones can be damaged by thermal shock, do not expose to extreme temperature changes. Steam cleaning no Ultrasonic cleaning no

Pearl (Freshwater pearl, Südsee-Perle, Tahitian Pearl)

Enhancement Bleached, dyed, chemically enhanced or irradiated. Most perls are cultured. Explanation Occasionally used to change, improve the colour and/or colour uniformity. Care for Clean by gently wiping with a moist cloth Steam cleaning no Ultrasonic cleaning no

Pearl (Mabe Pearl)

Enhancement A Mabe Pearl is a hemispherical shaped Pearl that is grown against the inside of the oyster's shell and is cut out of the shell with a circle-bit drill. The nucleus is replaced with resin and the back capped with a piece of Mother of Pearl. It can also be bleached, dyed, chemically treated or irradiated. These Pearls are classified as composite gemstones. Explanation Is used for manufacturing. Further optional enhancements are occasionally used to improve colour and/or change colour and/or colour uniformity. Care for Clean by gently wiping with a moist cloth Steam cleaning no Ultrasonic cleaning no

Mother of Pearl (Mother of Pearl)

Enhancement Dyed, bleached or coated. Explanation Occasionally used to change, improve the colour and/or colour uniformity. Care for Clean by gently wiping with a moist cloth Steam cleaning no Ultrasonic cleaning no

Petalite

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Pezzottaite (Pezzottaite)

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Phenakite

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Phosphosiderit

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Pietersit

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Prehnite

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Psilomelan

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Quartz (Rainbow Quarz)

Enhancement Irradiated, heated, PVD coated Explanation Usually applied to improve/intensify colour or produce unique colours. Physical Vapour Deposition (PVD) is an oxide enhancement that uses optical interference to produce a variety of colours by applying a bonded layer of fine titanium atoms to a gemstone (U.S. Patent Number 5,853,826 for Azotic Coating Technologies Inc.). Care for Coated or surface-treated gemstones can not be re-cut or re-polished. Steam cleaning no Ultrasonic cleaning no

Quartz (Dinosaur Bone)

Enhancement None Explanation Without explanation Care for Some gemstones can be damaged by thermal shock, do not expose to extreme temperature changes. Steam cleaning no Ultrasonic cleaning no

Quartz (Amazon Quartz, Banana Quartz, Multicolour Quartz, Moonlight Quartz, Blueberry Quartz, Lily Quartz, Ouro Verde Quartz)

Enhancement Heated Explanation Usually applied to provide/improve colour. Care for None Steam cleaning yes Ultrasonic cleaning no

Quartz (Champagne Quartz, Cognac Quartz, Smoky Quartz)

Enhancement Irradiated and/or heated Explanation Usually applied to provide/improve colour. Care for None Steam cleaning yes Ultrasonic cleaning no

Quartz (Angelandia Rose Quartz, Black Estrelita Cats Eye Quartz, Black Estrelita Star Quartz, Black Rutile Quartz, Cats Eye Rutile Quartz, Dendritic Quartz, Dragonfly Quartz, Black Estrelita Cats Eye Quartz, Black Estrelita Star Quartz, Graffiti Quartz, Moss quartz, Milky Quartz, Medusa Quartz, Mutuca Rutile Quartz, Prince Quartz, Estrelita Star Rose Quartz, Rose Quartz, Rutile Quartz, Strawberry Quartz, Tourmaline Quarzt, Black Ceylon Rutile Quartz)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Quartz (Golden Glitter Quartz, Pearl Glitter Quartz, Titanblauer Glitter Quartz, Black Glitter Quartz, Bronze Glitter Quartz, Cobalt Blue Glitter Quartz, Green Glitter Quartz, Copper Glitter Quartz, Pearl Glitter Quartz, Pink Glitter Quartz, Platinum Glitter Quartz, Purpur Glitter Quartz, Silver Glitter Quartz, Flamingo Glitter Quartz, Neptune Glitter Quartz)

Enhancement Heated, irradiated or PVD coated Explanation Usually applied to improve/intensify colour or produce unique colours. Physical Vapour Deposition (PVD) is an oxide enhancement that uses optical interference to produce a variety of colours by applying a bonded layer of fine titanium atoms to a gemstone (U.S. Patent Number 5,853,826 for Azotic Coating Technologies Inc.). Care for Avoid bringing into contact with alcohol or other chemical substances. Wash with a damp cloth with as little water as possible. Also keep away from heat. Coated or surface-treated gemstones can not be re-cut and re-polished. Steam cleaning no Ultrasonic cleaning no

Quartz (Bordeaux Quartz, Cherry Quartz, Cobalt Blue Quartz, Fire Quartz, Flamingo Quartz, Golden Quartz, Jungle Quartz, Lotus Quartz, Marrequinho Quartz, Moonlight Quartz, Blue Mystik Quartz, Mystik Quartz, Neon Yellow Quartz, Neptune Quartz, Gentiana Quartz, Spring Quartz)

Enhancement PVD coated Explanation Usually applied to improve/intensify colour or produce unique colours. Physical Vapour Deposition (PVD) is an oxide enhancement that uses optical interference to produce a variety of colours by applying a bonded layer of fine titanium atoms to a gemstone (U.S. Patent Number 5,853,826 for Azotic Coating Technologies Inc.). Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions. Coated or surface-treated gemstones can not be re-cut or re-polished. Steam cleaning no Ultrasonic cleaning no

Quarzit

Enhancement Dyed and/or impregnated with colourless plastic or hardened resin Explanation Occasionally used to improve appearance. Care for None Steam cleaning Ultrasonic cleaning

Rhodochrosite (Rhodochrosite, Sweet Home Rhodochrosite)

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Rhodolite (Brasilian Rhodolite, Rasberry Rhodolite, Rajasthan Rhodolite)

Enhancement None Explanation Without explanation Care for Some gemstones can be damaged by thermal shock, do not expose to extreme temperature changes. Steam cleaning no Ultrasonic cleaning no

Rhodonite

Enhancement Natural or dyed Explanation Occasionally used to achieve colour uniformity. Care for None Steam cleaning no Ultrasonic cleaning no

Rubellite (AAA Cruzeiro Rubellite, Copper Rubellite)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Rubellite (Rubellite, Brazilian Rubellite)

Enhancement Natural or heated and/or irradiated Explanation Usually applied to provide/improve colour. Care for None Steam cleaning yes Ultrasonic cleaning no

Rubellite (Nigerian Rubellite, Cats eye Rubellite, Shimoyo Rubellite, Cats Eye Shimoyo Rubellite)

Enhancement None or occasional irradiation Explanation Only 10 % of Shimoyo Rubellite have been irradiated to improve their colour. Irradiated Tourmaline is almost impossible to detect and is therefore generally regarded as not impacting value. Care for None Steam cleaning yes Ultrasonic cleaning no

Ruby (Mozambique Ruby, Mozambique Cats Eye Ruby, Mozambique Star Ruby, Star Ruby)

Enhancement Heated and/or the healing of fissures/cavities with (a high refractive index) lead-glass or with certain additives (beryllium). Explanation Always used to improve colour intensity, to lighten colour and/or colour uniformity. The lead-glass is usually yellow to orange and artificially augments the red colour of these gems as well as potentially adding weight. Care for These gems may have fillers in cavities/voids, fissures and/or open fractures that can scratch more easily than the gem itself as well as being more vulnerable to damage from heat or some solvents. Steam cleaning no Ultrasonic cleaning no

Ruby (AAA Tanzanian Ruby, Malawi Ruby, Sunset Ruby)

Enhancement Heated and/or the healing of fissures and/or filled open cavities with certain additives (beryllium) Explanation Usually applied to provide, intensify or improve colour and/or uniformity of colour. Care for These gems may have fillers in cavities/voids, fissures and/or open fractures that can scratch more easily than the gem itself as well as being more vulnerable to damage from heat or some solvents. Steam cleaning yes Ultrasonic cleaning yes

Ruby (Orissa Star Ruby)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Ruby (Vietnamesian Ruby)

Enhancement Heated Explanation Usually applied to provide/improve colour. Care for None Steam cleaning yes Ultrasonic cleaning yes

Sapphire (AAA Ceylon Sapphire, AAA Imperial Sapphire, Blue Star Sapphire, Chanthaburi Sapphire, Inverell-Saphir, Mambila Sapphire, Pailin Sapphire, Padparadscha Sapphire, Tanzanian Sapphire, Imperial Sapphire)

Enhancement Heated (heated in a beryllium environment and may contain traces of beryllium) Explanation Usually applied to provide/improve colour. Care for None Steam cleaning yes Ultrasonic cleaning yes

Sapphire (Burmesian Sapphire, Laos Sapphire, Pink Ceylon Sapphire)

Enhancement Heated Explanation Usually applied to provide/improve colour. Care for None Steam cleaning yes Ultrasonic cleaning yes

Sapphire (Purple Ceylon Sapphire, Black Sapphire, Black Star Sapphire, 12 pointed Golden Star Sapphire, 12 pointed Black Star Sapphire)

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning yes

Sapphire (AAA Tansania Sapphire)

Enhancement Heated (heated in a beryllium environment and may contain traces of beryllium) Explanation Usually applied to provide colour and/or colour uniformity. Care for None Steam cleaning yes Ultrasonic cleaning yes

Sapphire (Colour Change Sapphire, Green Sapphire, Golden Star Sapphire, Kanchanaburi Sapphire, Midnight Blue Sapphire, Orange Sapphire, Padparadscha Colour Sapphire, Pink Ceylon Sapphire, Ceylon Sapphire, Rainbow Sapphire, Star Sapphire, White Sapphire, White Star Sapphire, Fancy Sapphire)

Enhancement Heated and/or the healing of fissures and/or filled open cavities with certain additives (beryllium) Explanation Usually applied to provide colour or colour uniformity, to intensify or lighten colour. Care for These gems may have fillers in cavities/voids, fissures and/or open fractures that can scratch more easily than the gem itself as well as being more vulnerable to damage from heat or some solvents. Steam cleaning yes Ultrasonic cleaning yes

Sard

Enhancement Dyed or heated Explanation Dyeing is occasional, while heating is usual. All provide colour. Care for None Steam cleaning yes Ultrasonic cleaning no

Scheelit

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Seraphinit

Enhancement None Explanation Without explanation Care for Very fragile, handle with care! Steam cleaning no Ultrasonic cleaning no

Serpentin

Enhancement Natural or dyed and/or impregnated with colourless plastic or hardened resin Explanation Occasionally used to improve appearance. Care for None Steam cleaning yes Ultrasonic cleaning no

Sinhalite

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Sillimanite (Sillimanite, Cats Eye Sillimanite)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Scapolite (Scapolite, Cats Eye Scapolite, Yellow Skapolith, Pink Skapolite)

Enhancement None Explanation Without explanation Care for Some stones fade when exposed to strong light. Do not unnecessarily expose gemstones to these conditions. Steam cleaning yes Ultrasonic cleaning no

Emerald (AAA Russian Emerald, Bahia Emerald, Muzo Colombian Emerald, Sao Francisco Emerald, Socoto Emerald, Transvaal Emerald)

Enhancement colourless oil. Explanation Infusions of colourless oil is a common method to improve appearance. Care for These enhancements can be damaged by some solvents and thermal shock. Steam cleaning no Ultrasonic cleaning no

Emerald (AAA Emerald, AAA Brasilian Emerald, AAA Sambian Emerald, Colombian Emerald, La Pita Emerald, AAA Nova Era Emerald, Panjshir Emerald, Russian Emerald, Sambian Emerald)

Enhancement Filled fissure with colourless oil, plastic, wax or resin. Colour enhancement with dyed oils. Filled fractures or cavities with synthetic resin. Explanation Commonly used to improve appearance Care for These enhancements can be damaged by some solvents and thermal shock. Steam cleaning no Ultrasonic cleaning no

Emerald (Trapiché Emerald)

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Sodalite

Enhancement Dyed Explanation Rarely used to improve colour. Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions! Steam cleaning no Ultrasonic cleaning no

Sunstone (Star Sunstone, Cats Eye Sunstone, Oregon Sunstone, Silver Sunstone)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Spektrolith

Enhancement Surface colourless waxing Explanation Occasionally used to improve appearance. Care for None Steam cleaning no Ultrasonic cleaning no

Spessartite

Enhancement None Explanation Without explanation Care for Extreme temperature changes can damage the gemstones. Steam cleaning no Ultrasonic cleaning no

Sphalerite

Enhancement None Explanation Without explanation Care for Very fragile, handle with care! Steam cleaning Ultrasonic cleaning

Sphene (Sphene, Capelinha Sphene, Russian Sphen)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Spinel (Spinel, Blue Spinel, Noble Red Spinel, Lavender Spinel, Pink Spinel, Pamir Spinel, Purple Spinel, )

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Sugilite

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Taaffeit

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Tanzanite (AAA Tanzanite)

Enhancement Heated Explanation Usually applied to provide/improve colour. Care for Some gemstones can be damaged by thermal shock, do not expose to extreme temperature changes. Steam cleaning no Ultrasonic cleaning no

Tanzanite (Tanzanite, Multicolour Tanzanite, Chameleon Tanzanite, Fancy Tanzanite, Cats Eye Tanzanite, Green Tanzanite, Neon Tanzanite, Yellow Tanzanite, Pink Tanzanite)

Enhancement None Explanation Without explanation Care for Some gemstones can be damaged by thermal shock, do not expose to extreme temperature changes. Steam cleaning no Ultrasonic cleaning no

Tigers Eye (Tigers Eye)

Enhancement Dyed, bleached or heated Explanation Commonly used to improve colour. Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions! Steam cleaning Ultrasonic cleaning

Tigers Eye (Red Tigers Eye)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Topaz (AAA Imperial Topaz, Imperial Topaz, Gletscher-Topas, Ukranian Topaz, White Topaz)

Enhancement None Explanation Without explanation Care for None Steam cleaning no Ultrasonic cleaning no

Topaz (London Blue Topaz, Marambaia-Topas, Ocean Topaz, Sky Blue Topaz, Swiss Blue Topaz)

Enhancement Irradiated and/or heated Explanation Usually applied to provide and/or improve colour. Care for None Steam cleaning no Ultrasonic cleaning no

Topaz (Sunset Mystic Topaz, Flamingo Topaz, Fire Topaz, Cherry Topaz, Kiwi Topaz, Laguna Topaz, Ocean Topaz, Moonlight Topaz, Mystic Topaz, Neptune Topaz, Sunset Topaz, Grape Topaz, Watermelon Topaz, Jungle Topaz, Gentiana Topaz, Fire Topaz, Fire Topaz, Spring Topaz, Cobaltblauer Topaz, Marrequinho Topaz, Orchid Topaz, Rose Topaz, Canari Topaz, Neon Blue Mystik Topaz, Paradise Topaz, Cranberry Topaz, Chocolate Topaz, Lime Topaz, Passion Fruit Topaz, Regenbogen-Topas, Champagne Topaz, Chameleon Topaz, Golden Topaz, Orange Topaz, Pazific Topaz, Vanilla Topaz, Azur Topaz, Blue Mystik Topaz, Iris Topaz, Aurora Topaz, Blue Topaz, Pink Topaz)

Enhancement Erhitzen, PVD-Ummantelung Explanation Usually applied to improve/intensify colour or produce unique colours. Physical Vapour Deposition (PVD) is an oxide enhancement that uses optical interference to produce a variety of colours by applying a bonded layer of fine titanium atoms to a gemstone (U.S. Patent Number 5,853,826 for Azotic Coating Technologies Inc.). Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions. Coated or surface-treated gemstones can not be re-cut or re-polished. Steam cleaning no Ultrasonic cleaning no

(Tsavorite)

Enhancement None Explanation Without explanation Care for Some gemstones can be damaged by thermal shock, do not expose to extreme temperature changes. Steam cleaning no Ultrasonic cleaning no

Turquoise (South Western Turquoise)

Enhancement Impregnation with plastic and/or surface colourless waxing Explanation Impregnation is rarely used, waxing is commonly used. All improve stability, durability, lustre and/or colour. Care for None Steam cleaning no Ultrasonic cleaning no

Turquoise (Purpur Turquoise)

Enhancement Constructed/impregnated with plastic and/or surface colourless waxing and/or dyed. Explanation Dyeing is rare, while impregnation with colourless plastic and surface colourless waxing is common. All improve stability, durability, lustre and/or colour. Care for None Steam cleaning no Ultrasonic cleaning no

Tourmaline (AAA Cruzeiro Rubellite, Chrome Tourmaline, Colourchange Chrome Tourmaline, Himalaya Tourmaline, Green Namibia Tourmaline, Canari Tourmaline, Cats Eye Tourmaline, Kunar Valley Tourmaline, Multicolour Tourmaline, Multicolour Namibian Tourmaline, Mint Tourmaline, Mint Pirineu Tourmaline, Olive Tourmaline, Pink Copper Turmalin, Pirineu Tourmaline, Cats Eye Pirineu Tourmaline, Blue Green Sapo Tourmaline, Red Sapo Tourmaline, Pink Sapo Tourmaline, Black Tourmaline, Watermelon Tourmaline)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Tourmaline (AAA Paraíba Tourmaline, Brazilian Rubellite, Sunset Copper Tourmaline, Brasilian Paraíba Tourmaline, Yellow Copper Tourmaline, Indicolite, Canari Copper Tourmaline, Imperial Copper Tourmaline, Copper Tourmaline, Copper Rubellite, Multicolour Copper Tourmaline, Morro Redondo Pink Tourmaline, Neon Copper Tourmaline, Nigerian Pink Tourmaline, Nigerian Rubellite, Paraíba Tourmaline, Pink Tourmaline, Rubellite)

Enhancement Natural or heated and/or irradiated Explanation Usually applied to provide/improve colour. Care for None Steam cleaning yes Ultrasonic cleaning no

Tourmaline (Multicolour Mutuca Indicolite, Mutuca Indicolite, Cats Eye Mutuca Indicolite, Itatiaia Tourmaline , Oyo Tourmaline, Santa Rosa Tourmaline)

Enhancement Heated Explanation Usually applied to provide/improve colour. Care for None Steam cleaning yes Ultrasonic cleaning no

Tourmaline (Shimoyo Rubellite, Cats Eye Shimoyo Rubellite, Cats eye Rubellite)

Enhancement None or occasional irradiation Explanation Only 10 % of Shimoyo Rubellite have been irradiated to improve their colour. Irradiated Tourmaline is almost impossible to detect and is therefore generally regarded as not impacting value. Care for None Steam cleaning yes Ultrasonic cleaning no

Unakit

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Zircon (AAA Ratanakiri Zircon, Blue Zircon, Fancy Zircon, Imperial Zircon, Kaduna Zircon, Canari Zircon, Ratanakiri Zircon, Preah Vihear Zircon, White Zircon)

Enhancement Heated Explanation Always used to improve colour. Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions! Steam cleaning yes Ultrasonic cleaning no

Zircon (Multicolour Zircon, Saffron Zircon)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no

Zircon (Cinnamon Zircon)

Enhancement Natural or heated Explanation Used in order to enhance the colour Care for Some gemstones may fade or revert to their original colour when exposed to strong light, do not unnecessarily expose gemstones to these conditions! Steam cleaning yes Ultrasonic cleaning no

Zoisit (Ruby in Zoisite)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning yes

Zultanite (Zultanite, Cats Eye Zultanite)

Enhancement None Explanation Without explanation Care for None Steam cleaning yes Ultrasonic cleaning no