Typically colorless with a “sleepy” look, cryolite is rarely found in nature. Rough suitable for gem faceting is extremely scarce. […]

Lovely saffron-colored crocoite is quite a rare mineral. Although too soft and brittle for jewelry wear, a few crystals have

Probably fewer than a dozen creedite gems have ever been faceted. This rare mineral is rarer still as a cuttable

Although covellite has attractive blue colors and shows iridescence, this rare mineral is difficult to cut. You can scratch it

Next to diamond, corundum is the hardest mineral known and is very compact and dense, with no cleavage. As a

The crystal structure of cordierite has many similarities to that of beryl; indialite, the dimorph, in fact has the same

Coral is the external skeleton of a tiny, plant-like marine animal called the coral polyp. The structures that result from

Color change sapphires are those that change color between light sources.

Any stone that changes color under different types of light is a rare treat for collectors. Color change garnets show

Colemanite is an abundant mineral, and transparent material isn’t rare. However, gem cutters rarely facet these typically pale stones. Difficult