Unknown until recently, Sphene is a marvelous precious stone with incredibly fire that has the potential to rival the much more popular Diamond.
Sphene owes its name to the Greek ‘Sfena’ - wedge - due to its wedge-shaped crystals. Sphene is also sometimes called Titanite due to the high Titanium content.
Chemical composition of Sphene
Sphene is a silicate of calcium and titanium, and owes its color to the presence of iron. Its color ranges from yellow-green to green and even brown hues. Due to its low hardness (5 - 5.5 on Mohs’ scale), it is a difficult gem to cut.
The principle Sphene deposit lies in Madagascar, but a few examples have also been extracted in Brazil, Canada, Mexico, Myanmar, Austria, Pakistan, Sri Lanka and the U.S. The raw material is extracted directly from the mother rock, also known as effusive rock.
The history of Sphene
This Titanium mineral was first discovered in 1795 in Hauzenberg, in the Bavarian forest. Sphene is a relatively new gemstone to the market, and thus has no myths or traditions associated with it.
A raw crystal of Capelinha Sphene
Properties of Sphene
The fire (dispersion of light into the colors of the spectrum) is greater than Diamond or Demantoid, and is always linked to the color of the gem: if the color is too intense, Sphene’s fire risks not being seen. The luster of Sphene is close to that of Diamond, and is referred to as ‘adamantine’ (‘similar to Diamond’). A not to forget the double refractivity, thanks to which light is split into two components, or rays, conferring great optical depth upon Sphene.
Its pleochroism also makes it appear as though Sphene changes color; this property causes diffracted light to display different colors depending on the angle of view.
Normally, Sphene is transparent and possesses crystalline purity - inclusions visible to the naked eye are rare, and disrupt its natural beauty.
Varieties of Sphene
One rare variety of Sphene is Capelinha Sphene, named for the Brazilian city famed for its mines. This variety of Sphene, with its unique lime green hue, also called Chartreuse, is among the most beautiful and most rare; currently, Sphene is no longer extracted from Capelinha.