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Articles on My favourite gem

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Diamond or zirconia? Apart from the price, it can be hard to tell these two gems apart. from www.shutterstock.com

A disappointing earring, and the world’s hottest rock: zirconia

Zirconia is a mineral with a crystal structure made from the elements zirconium and oxygen. It looks pretty like diamond, but is only worth a fraction of the value.
The first three Natural History Museum painites – including one in its natural state with rubies that had been sitting in their collection for years. It had initially been misidentified as the much less valuable tourmaline. © The Trustees of the Natural History Museum, London

What is a gem? And why painite from Myanmar can fetch US$60,000 per carat

What makes a stone a gem? It boils down to a few key qualities: beauty and durability. But opal, the national gemstone of Australia, is an anomaly - it’s soft.

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