pezzottaite-(Cs)

Pezzottaite, marketed under the name raspberyl or raspberry beryl, is a mineral species first recognized by the International Mineralogical Association in September 2003. Pezzottaite is a caesium analogue of beryl, a silicate of caesium, beryllium, lithium and aluminium, with the chemical formula Cs(Be2Li)Al2Si6O18. Named after Italian geologist and mineralogist Federico Pezzotta, pezzottaite was first thought to be either red beryl or a new variety of beryl ("caesium beryl"); unlike actual beryl, however, pezzottaite contains lithium and crystallizes in the trigonal crystal system rather than the hexagonal system.

== Appearance == Colors include shades of raspberry red to orange-red and pink. Recovered from miarolitic cavities in the granitic pegmatite fields of Fianarantsoa province, southern Madagascar, the pezzottaite crystals were small—no more than about in their widest dimension—and tabular or equant in habit, and few in number, most being heavily included with growth tubes and liquid feathers. Approximately 10 percent of the rough material would also exhibit chatoyancy when polished. Most cut pezzottaite gems are under one carat (200 mg) in weight and rarely exceed two carats (400 mg).