Gemology: I is for...

This week we're continuing our delve into gemology with gemstones beginning with I. Welcome to the world of Idocrase, Imperial Topaz, Inca Rose, Iolite, and Ivory.

Idocrase (Vesuvianite) Idocrase is another name for Vesuvianite, which was named for Mt Vesuvius in Italy, the place where it was first described after being found near lava flows. In fact, Vesuvianite is the more common name for this mineral with Idocrase now only being seen in old text books and indexes. Idocrase is generally a dull gem, often in shades of brown and yellow, but there are some instances of highly coloured and vibrantly radiant gemstones out there. These rarer lustrous colours, found in Quebec, occur in shades of red, pink, orange, purple and blue, and – even more rarely – several shades all at once!

Idocrase Vesuvianite Crystal

Imperial Topaz Imperial Topaz, also known as Precious Topaz, is a rare, highly collectible crystal gemstone with colours described as 'the setting sun' – a glorious pinkish-orange! It gets the name Imperial Topaz from the Russian Tsars in the 17th century who claimed all rights to any samples mined in Russia. Nowadays samples found in yellow, pink and purple are accepted as Imperial Topaz by analysis of their hardness on the Mohs scale and crystal structure. Imperial Topaz makes a fantastic gemstone for jewellery, being cut into many faceted gemstone shapes.

Imperial Topaz Uncut Crystal