Sphene

Sphene Information

For your gem needs see our Recommended Suppliers.

CHEMISTRY CaTiSiO5
CRYSTALLOGRAPHY Monoclinic
REFRACTIVE INDEX 2.054 - 1.880
HARDNESS 5 to 5.5
SPECIFIC GRAVITY 3.50 - 3.54
CLEAVAGE Weak, in two directions
HEAT SENSITIVE Yes

WEARABILITY* Poor
SPECIAL CARE INSTRUCTIONS See text

ENHANCEMENTS None

*Wearability is graded as Excellent, Very Good, Good, Poor, and Forget It!
For more details see the article on "Hardness and Wearability."

Sphene     Sphene is also known as "titanite" due to its titanium content. They are yellow, orange, brown or green gems with many gradations between those colors. The usual colors are created by iron and rare-earth element impurities. Sphene is found primarily in Madagascar, Mexico, Canada and, historically, in Austria. Although reasonably available in the marketplace, it is virtually unknown to the general public.
    Several gemological characteristics make it beautiful and desirable as a collector's stone or, with care, for jewelry use. Its dispersion, (fire,) is one of the highest of all gem materials and is higher than diamond. The body color, degree of inclusions, cutting orientation and cutting style may enhance or obscure this feature. If well polished, the luster can approach or equal that of diamond, but the gem is difficult to polish well. The high birefringence usually makes some doubling of facet images visible within the stone giving it a degree of internal fuzziness similar to that often seen in zircon or peridot. A rare variety termed chrome sphene is colored by chromium and is an intense green. Enhancements, imitations or synthetics are not known.
    This gem is somewhat risky as a jewelry stone due to its softness and brittleness, but beautiful if set protectively and worn occasionally. Shield this gem from knocks, heat and exposure to acids; do not clean with steam or ultrasonics, and it will be a spectacular addition to your gemstone collection or jewelry case.

Value

    As is so common in gemstones, color, clarity and size are the most important value factors, followed by the skill and artistry shown in cutting. A preference exists for stones that are lighter in tone, especially yellows, light oranges and greens which are able to best exhibit this gem's magnificent dispersion. Size is definitely a premium characteristic with this species. Chrome sphene is the most valuable type. In general, specimens with reasonably good clarity, (this stone is rarely even eye clean,) strong and attractive body color and showing at least some dispersion command the best prices.

Text and photos courtesy of Barbara Smigel at Artistic Colored Stones.

Back to the Index of Gemstones