BERYL
(as a group)

(top - left to right): Emerald (green) : Goshenite (colourless) : Morganite (pink/peach)

(bottom - left to right): Heliodor (yellow) : Aquamarine (blue)

This mineral occurs as prismatic crystals, which are sometimes terminated with small pyramids. The crystals are often striated parallel to their length, and may be of vast size. It also forms in massive, compact, and columnar habits. The streak is white. Beryl is transparent to translucent, with a vitreous lustre. It forms in pegmatites and granites and in some regionally metamorphosed rocks.

Group: Silicates

Composition: Be3Al2Si6O18

Hardness: 7-8

Specific Gravity: 2.6-2.9

Cleavage: Indistinct

Fracture: Uneven to conchoidal