1. Untreated coloured gemstones
About 90 per cent of gemstones are heated to improve their colour or clarity. Some of the rarest untreated coloured gemstones are Kashmir sapphires, so it’s likely these will be very popular at auction this year.
2. Pink diamonds
Less than 0.1 per cent of diamonds mined worldwide are pink and they are only found in certain areas, such as the famous Argyle mines in Kimberley, Western Australia. Last year, the Argyle mines closed for good, and prices for pink diamonds reportedly shot up 40 per cent.
3. Spinels
For hundreds of years, people believed that rubies and spinels were the same stone. Look for spinels that are unheated and preferably from Myanmar. A strong colour with as few inclusions as possible is also desirable.
Related: Arte Oro Hosts Tatler Friends to Discover Investment-Worthy Gemstones