Phenakite Locality: Jos Plateau, Plateau State, Nigeria (Locality at mindat.org) Size: miniature, 4.7 x 3.7 x 2.4 cm Phenakite A 50-gram specimen that is among — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Phenakite
Also known as: Phenacite.
Beryllium orthosilicate — a rare colorless gem mineral with rhombohedral crystals.
Intro adapted from Wikipedia (CC BY-SA).
Phenakite is an IMA-recognized mineral species in the silicate class, with the chemical formula Be₂(SiO₄).
It crystallizes in the hexagonal crystal system (space group R-3). It is a member of the Phenakite structural group.
Key properties: Mohs hardness 7.5–8; specific gravity 2.93–3; typically colorless or white or yellow or pink or brown; white streak; Vitreous luster; refractive index 1.661; optically uniaxial.
IMA symbol Phk, grandfathered status — known before the IMA’s founding, named in 1833.
Found in pegmatites, greisens, and alpine and hydrothermal veins.
It is found associated with Topaz, beryl, chrysoberyl, fluorite, muscovite, quartz.
Its name comes from the Greek for deceiver, in allusion to its similarity to quartz when colorless.
Collections: Gemstones, Collector Favorites, Rare & Remarkable.