Look up: Phenakite

1. Phenakite
   Phenakite has the formulae Be2SiO4 and a relative hardness of 8. It is a rare mineral found in pegmatite dikes associated with topaz, beryl, and apatite. From the Greek word for 'a deceiver' in that it can be mistaken for quartz.
   Found on http://www.probertencyclopaedia.com/brow
   
   
2. phenakite
   rare mineral, beryllium silicate, Be2SiO4, used as a gemstone. Phenakite has long been known from the emerald and chrysoberyl mine on the Takovaya ...
   Found on http://www.britannica.com/eb/a-z/p/55
   
   
3. Phenakite
   `Phenakite` or `phenacite` is a fairly rare nesosilicate mineral consisting of beryllium orthosilicate, Be₂SiO₄. Occasionally used as a gemstone, phenakite occurs as isolated crystals, which are rhombohedral with parallel-faced hemihedrism, and are either lenticular...
   Found on http://en.wikipedia.org/wiki/Phenakite