Gem Library

BUYER’S OVERVIEW:
Sphalerite is considered to be a semi-precious gemstone and while limited in nature, gems of good color and size are available, however, faceted stones above 1 carat are rare. Despite being soft and somewhat fragile, Sphalerite’s brilliance, dispersion greater than diamond, deep earthy colors and vivid three dimensional inclusions, make it a unique and exquisite gemstone that is keenly sought after by gemstone collectors and connoisseurs alike. Currently, the most in demand colors of Sphalerite are the earth toned oranges and honey brown.

COLOR:
Sphalerite comes in a range of colors including yellow, green, orange, red, brown and black.

APPEARANCE:
Transparent to opaque, Sphalerite is usually highly included.

SIZE RANGE:
1 to 10 carats, clean stones above 1 carat are rare but stones of 30 carats are known.

TYPICAL CUTTING STYLES:
Transparent: most cutting styles are available.
Translucent: cabochons

POSSIBLE ENHANCEMENTS & TREATMENTS:
Sphalerite has no known enhancements.

HARDNESS:
3½ to 4 on the Mohs scale.

BEST USE OF THE GEMSTONE:
Sphalerite is not a strong gemstone and as such, earrings, pendants, pins, and tie tacks are probably the safest choice for this stone. Rings should be limited to occasional wear and the stones should be set with a protective setting.

CARE & CLEANING:
It is best to never expose colored gemstones to cleaning solvents or chemicals of any kind.
Common cleaning methods include:
Ultrasonic: never
Steamer: never (very heat sensitive)
Warm soapy water: safe
Reaction to Chemicals: can be damaged by acids.
Reaction to Heat: very heat sensitive
Stability to Light: generally stable after prolonged exposure to sunlight or UV light.

INTERESTING FACTS ABOUT THIS GEMSTONE:
The name Sphalerite comes from the Greek word “sphaleros”, which means misleading or treacherous, an allusion to the ease with which Sphalerite is mistaken for the mineral Galena by miners searching for lead. Sphalerite, also known as Zinc Blende, is a major ore of Zinc. When pure (little or no Iron) it forms clear crystals, usually red (Ruby Blende), but as the Iron content increases it forms dark, opaque metallic crystals. The black variety is called marmatite and has also been called black-jack, by miners. Some Sphalerite specimens, especially those found near Franklin, New Jersey will actively fluoresce orange and / or blue under longwave ultraviolet light and are known by the name of Cleiophane, an almost pure Zinc Sulfide variety. Sphalerite has high dispersion and at 0.156 it is over three times that of diamond. A well cut Sphalerite could conceivably be mistaken for a fancy-colored diamond, however, Sphalerite is softer and more fragile. Collectors pay a premium for stones over 1 carat as clean crystals are usually quite small. The two most important sources for Sphalerite are the Chivera mine in Mexico and the Picos de Europa mine near Santander on Spain’s northern coast.

DESIGNATION:
This gem has a long history but has no traditions currently associated with it.

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