Topaz

Topaz comes in more colours than most people expect: colourless, light blue, yellow, orange, pink, violet, brown and, very rarely, red. The most prized is Imperial topaz, a pinkish orange; the usual story is that it was named for the Russian royal family, who kept the finest stones for themselves.

Topaz is not mined in South Africa. Its major African sources today are Namibia, Nigeria and Madagascar. In Namibia it is found around Klein Spitzkoppe, in the Erongo region.

Blue topaz, honestly

Topaz can grow a natural pale sky blue. But almost all the deep, vivid blue topaz you will see is colourless topaz that has been irradiated and heated. The colour is permanent. It is the standard way blue topaz is made, so it is not listed piece by piece; any other treatment we know of, we tell you. The rainbow "mystic" topaz is different again: a colourless stone with a thin coating on its surface.

Beliefs and legends

In ancient Egypt, topaz was linked with Ra, the sun god. The Greeks believed it gave strength; in Renaissance Europe it was said to break spells and calm anger; and in India, worn above the heart, it promised long life, beauty and intelligence.

What it is

Topaz is an aluminium silicate containing fluorine, 8 on the Mohs scale. It is hard, but it has poor toughness: a sharp knock can chip it or split it along one direction.

How to judge a topaz

• Colour first. In blue topaz, choose the shade you love, from pale sky to deep inky blue. In Imperial topaz, the pinkish oranges are the most prized.
• Clarity: choose a stone that looks clean to you.
• Cut: topaz is brilliant when it is cut well; look for life across the whole face.

Caring for your topaz

Clean it in warm soapy water. Never use steam or an ultrasonic cleaner, and keep it away from high heat and sudden changes of temperature, which can cause internal breaks. Wear rings with a little care.

At a glance