How to choose a sapphire

Most people start a sapphire search with carat weight and a budget. We'd gently suggest the opposite: start with colour, because it's the one thing you can't change later.

Colour is the price

Two sapphires of identical weight can differ in price by a factor of ten on colour alone. The stones that hold their value sit in a band the trade calls cornflower — vivid without tipping into inky darkness.

If the colour still reads as blue across the room in the evening, it will read as blue for the rest of your life.

What to ask for

• Ask to see the stone in daylight, incandescent light, and shade — good blue survives all three.
• Ask whether the stone is heated. Heat treatment is routine and honest; it should simply be disclosed and priced accordingly.
• Ask for the origin paperwork if the price implies it — Kashmir and Burma command premiums that need evidence.

Certificates