What we look at
- Carat weight (1 carat = 0.2 grams)
- Colour, from completely colourless to yellowish
- Clarity, meaning inclusions
- Cut and proportions
- The metal and weight of the setting
Coloured gemstones
Sapphires, rubies and emeralds are assessed on colour, size and whether the stone has been treated. Smaller stones in older jewellery rarely have a resale value of their own, but the setting may.
