Further reading

Burmese rubies: sanctions, supply and value

Rubies from Myanmar are among the most sought-after stones in the world. Trade restrictions and rising prices raise a simple question for collectors: what happens to supply and to value?

Coloured stones and white diamonds: two different markets

Diamonds and coloured precious stones are often put in the same category, but they follow very different rules. Understanding the difference is the first step to buying well.

Why a laboratory certificate is not enough

A certificate from a recognised laboratory is essential for any important stone. But it only answers some of the questions that decide what a stone is worth.

Preserving and passing on wealth with precious stones

For centuries, families have used precious stones to preserve their wealth and to pass it on.

The ABC of the Big Four

Rubies, sapphires, emeralds and diamonds are the four precious stones of the trade. Three criteria classify them: beauty, rarity and durability. Three further elements determine their value: origin, weight and treatments.

What public auction results tell us about value

Our statistical analysis of thousands of sapphires sold at public auction since 2010: what origin, heating and laboratories do to the price.

Will sanctions and inflation weigh on the gemstone market?

Elke Berr on sanctions against Russian diamonds, how much supply is really affected, and why traceability depends on reliable suppliers.