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This month's
stone profile: |
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Sphene |
a.k.a.: titanite |
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| Refractive Index:
1.84-2.03 |
Crystal Structure:
Monoclinic |
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| Hardness: 5 |
Specific Gravity:
3.53 |
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| Chemical
Composition: Calcium titanium silicate |
Occurrences:
Mexico, Brazil, Canada and Madagascar |
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Though well known by collectors, sphene has only recently come onto the radar of many jewelry consumers.
As retailers are faced with stiffer competition for the next gemstone trends, we
have begun to see stones once thought unsuitable for jewelry applications being
set and actively promoted. Couple this with a dramatic increase in supply
over the last decade from Madagascar and you have the emergence of sphene's
popularity.
With a dispersion greater than that of diamond,
sphene certainly carries a dramatic flash for a
natural material. It is strongly doubly refractive (clearly visible as
doubling of the facets in the above photo) but is limited in use by its
durability. Sphene's now less common alternative name is titanite, a reference to its
chemical composition. Though usually some variation on
yellowish-green or brown, sphene is also rarely found in a pure saturated green
that is usually referred to as 'chrome' sphene.
Appreciation, and thus demand, for sphene has
definitely seen an upswing and production has been pressured to keep up.
That makes an ideal situation for prices to rise, so stay tuned.
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