Sphalerite oval pendant sterling silver

Hand polished sphalerite sterling silver oval bezel necklace.
13mm x 11mm

Sphalerite is zinc sulfide (ZnS) found throughout the world. In the 1800s it was known as "blende", or "zinc blende." In its pure form, sphalerite is colorless. However, this is extremely rare in nature. Gem quality sphalerite exhibits green or orange hues that can be cut with brilliant dispersion.

Sphalerite crystals from Illinois feature zinc atoms that have been heavily replaced by Fe and other elements which lends to its resinous brown or black appearance. It is not well known in the gemological world and polished cabochons can be easily mistaken as hematite.

This particular example I collected from a Paleozoic near-surface carbonate-hosted Mississippi Valley-type (MVT) ore deposit in northern Illinois. I can supply an XRF analysis of its composition, if you're into that sort of thing.

I wish to be fully transparent with the materials I utilize for my jewelry, both in grade and ethical sourcing. Tradition dictates and markets to the public what is supposed to be rare and beautiful. However, we all know that beauty belongs to the eye of the beholder and therefore cannot be quantified. The stones I use are "medium-low grade." The mnemonic, color, clarity, cut and carat weight (4Cs) was invented in the 1940s to standardize diamond marketing and appraisal. Color is subjective. Clarity refers to microscopic inclusions within the crystal that may or may not be visible with the naked eye. Cut refers to the precision of the cut and resulting light dispersion. Carat weight is obvious. The 4Cs are only useful if you're looking to invest thousands of dollars on jewelry that you probably wouldn't want to wear on a daily basis. Therefore, the 4Cs are irrelevant here. It is the flaws of natural stones that describe a more fascinating and complex genesis.