Sphene (Titanite)

Common mineral of the silicates and germanates class.
The mineralogical name is "titanite".

Origin of name: first found 1795 in the graphite mines of Hauzenberg, Bavaria, the mineral was named by German chemist Martin Heinrich Klaproth because of it´s titanium content.

Synonyms and trade names: Sphene, from Greek σφήν sphén ("wedge"), because of the often wedge-shaped crystals

Can be confused with: e.g.Zircon, Spalerite, Scheelite. Because of the extremely high dispersion ("fire"), green titanite could be confused with demantoid garnet.

Handling: due to it´s relatively low hardness, distinct cleavage and sensitivity to acids (fully soluble sulphuric acid!) brines and heat (unset before soldering!), titanite´s suitability as a gem stone is limited. Do not clean ultrasonically, no galvanic baths, shock-sensitive. Handle with great care.

Gemmological Properties of Sphene (Titanite)

Formula:

CaTi(SiO₄)O

Crystal system:

monoclinic

Mohs hardness:

5 - 5.5

Specific gravity:

3.48 - 3.60

Refractive index:

1.84 - 2.11 biaxial (+)

Max. Birefringence:

0.100 - 0.160

Dispersion:

extreme

Pleochroism:

colourless, yellow to green, orange to red

Luminiscence:

weak brown in shortwave UV

Lustre:

adamantine to resinous

Cleavage:

distinct

Fracture:

conchoidal, brittle

Colour:

colourless, grey, yellow, green, brown, orange, red

Gemmological Properties of Sphene (Titanite)

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