Information about Chrysoberyl

Chrysoberyl is a beryllium aluminium oxide mineral known for its remarkable hardness and brilliance. It typically forms as transparent to translucent prismatic or tabular crystals, often exhibiting a yellow-green to golden colour, although colourless and brownish varieties also exist.

One of its most striking forms is cat’s eye chrysoberyl (cymophane), which displays a silky, glowing band of light across the surface due to fibrous inclusions.

The extremely rare and colour-changing variety alexandrite, which appears green in daylight and red in incandescent light, is also a form of chrysoberyl.

Uses and History

Chrysoberyl is highly prized in the gemstone industry, particularly for cat’s eye chrysoberyl and alexandrite.

These varieties are considered precious gemstones, with alexandrite ranking among the rarest and most valuable in the world. Due to its high hardness (8.5 on the Mohs scale), it is also durable enough for everyday jewellery. Industrial uses are minimal due to its rarity and gem quality.

Chrysoberyl has been known and valued since antiquity, but the discovery of alexandrite in Russia’s Ural Mountains in 1830 brought significant attention to the mineral.

Named in honour of Tsar Alexander II, alexandrite became a symbol of Russian aristocracy. The phenomenon of chatoyancy in cat’s eye chrysoberyl was also celebrated in India and Sri Lanka, where the gemstone has long been revered for its perceived protective powers.

Mineralogy

Hazards and Warnings

Mineral collectors should wash their hands after handling specimens, to avoid any exposure to potential toxins.

Almost all rocks, minerals (and, frankly, almost all other substances on earth) can produce toxic dust when cutting, which can cause serious respiratory conditions including silicosis.

When cutting or polishing rocks, minerals, shells, etc, all work should be done wet to minimise the dust, and a suitable respirator or extraction system should be used.

Translations

Further Reading / External Links

• https://www.mindat.org/min-1039.html
• https://webmineral.com/data/Chrysoberyl.shtml
• https://www.minerals.net/mineral/chrysoberyl.aspx
• https://en.wikipedia.org/wiki/Chrysoberyl