Sphalerite is a sulfide that is predominantly associated with zinc, but almost always also contains up to 25% iron by weight. Within the industry, it is noted for being the primary ore used for zinc extraction, with miners having previously referred to it as “zinc blende”.

In certain directions, sphalerite crystals are able to display a diamond-like adamantine luster, and the mineral also possesses three times more spectral “fire” than diamond. As a result, sphalerite is also appreciated for its visual beauty, and high-clarity red, orange, yellow and/or green material is therefore occasionally faceted for collectors. However, the mineral’s extreme softness (3.5 to 4.0) – especially when combined with the fact it possesses a vulnerable perfect cleavage in six directions – makes sphalerite far too fragile for use within gem-set jewelry.