Gemstone Glossary

Phenakite

Phenakite is a rare, colorless mineral stone that is sometimes also found in tinted yellow, brown and pink shades. The name Phenakite is from the Greek word 'Phenakos' meaning "Deceiver", referring to its deceptively similar look to Quartz.

Phenakite is a beryllium mineral found as vitreous crystals in beryllium-rich granite pegmatites. It is composed of Beryllium silicate (Be2SiO4). Phenakite’ s hardness is ranked 7.5 to 8 on the Moh’s Scale with a Specific Gravity of approximately 2.9 - 3.0. Its crystals are commonly vitreous and transparent, however some translucent specimens have also been reported.


Twinning is common in Phenakite’s crystals and often results in penetration twins that appear to have a second platy crystal growing into another crystal. The twins can look like a normal crystal that has been folded. By far, this is the most interesting form and highly favored among mineral collectors.

A rare mineral, Phenakite is commonly found in association with several other gemstones such as Topaz, Cassiterite, Calcite, Hematite, Beryl (especially Emerald), Chrysoberyl and Smoky Quartz. Its occurrence has been reported at sites on the Takowaja River, Ural Mountains, Russia; Minas Gerias, Brazil; Pala, San Diego Co., California; Mt. Antero and Pikes Peak, Colorado, USA; and Norway.

Phenakite is quite a popular mineral for collectors, especially the twinned crystal forms. It is sometimes cut as a gemstone. Although somewhat lacking in color and fire, fine clear Phenakite crystals with good hardness can make good choices for gemstones. Phenakite’s rarity also contributes to its occasional use as a gemstone.