Chrysoberyl occurs in a variety of colours, from green, greenish yellow, and yellow to brown. It's a hard, durable stone, particularly suitable to be used in jewellery. When cut well, gems are brilliant but lack fire. Two varieties, alexandrite and cat’s-eye, have unique qualities that belongs to them. The rare and valuable alexandrite changes from green in daylight to red, mauve, or brown under incandescent light, like a lamp. Synthetic chrysoberyl, synthetic corundum, and synthetic spinel have been produced to mimic alexandrite’s colour change.
Cat’s-eye, when cut “en cabochon”, includes a near-white line across a yellowish grey stone, because of canal or feather-like fluid inclusions, or needle-like inclusions of rutile. Probably the most highly prized cat’s-eye colour is an easy golden brown, often having a shadow that provides an easy and dark, “milk and honey” effect. Pale yellow chrysoberyl, popular in 18th and 1800s Portuguese jewellery, was also called chrysolite.
Although mainly exercised, the very best chrysoberyl, including alexandrite, has been discovered in mica schists within the Urals (Russia). The biggest faceted chrysoberyl from Russia weighs 66 carats. Large waterworn pebbles of numerous colours are simply within the gem in Burma, Brazil, Zimbabwe, Tanzania and Madagascar. Cat’s eye can be found in Sri Lanka, Brazil and China.
The name is in the Greek “chrysos”, meaning golden and “beryllos” which refers towards the beryllium content. Known for centuries in Asia, it had been highly valued for that protection it afforded in the “evil eye”.
