What are some rare photos of raw, rough and uncut gemstones?
Chrysoberyl crystalizes in the orthorhombic system and is often found as flat prismatic crystals. Some crystals, like this alexandrite from Tanzania are twinned and known as trillings, where the crystals inter grow and form flowers or cyclic twins that give the false appearance of hexagonal symmetry. Another feature is the stepped growth lines which are clearly visible on the surface of the crystal. Alexandrite is a very rare and very expensive variety of gem-quality chrysoberyl, and this specimen will cut several large alexandrites, hence the relatively high value.