Sapphire is September’s birthstone and a variety of corundum, the same mineral species as ruby. Blue is its best-known colour, but sapphires also occur in pink, yellow, green and colourless varieties. Red corundum is called ruby.
Look at the individual stone
Start with a colour you enjoy. Compare its hue, lightness and saturation in more than one everyday light. A dark sapphire is not automatically better than a lighter one: brightness and personal preference matter.
Next, look face-up at the cut. Does the centre look lively, or is there a large transparent area or a dark patch? Check inclusions and condition with guidance. Inclusions can be useful identification clues, but their presence alone does not prove natural origin.
Treatment and reports
Ask whether the sapphire is natural or laboratory-grown and what treatments have been disclosed. Heating, diffusion and fracture filling are different processes with different implications. If a report is available, check which conclusions it actually supports.
Star and colour change sapphires
A star sapphire is usually cut as a cabochon to show light reflecting from oriented inclusions. A colour change sapphire shows a different appearance under different light sources. View these effects in person rather than relying on one photograph.
Choosing sapphire jewellery
Sapphire ranks 9 on the Mohs hardness scale, but condition, treatment and setting still affect care. For a ring, compare the gem’s visible dimensions, setting height and how it sits on the hand. Ask for care advice for the particular piece.
Illustrations and examples
Questions buyers ask
Are all sapphires blue?
No. Sapphire comes in several colours; red corundum is ruby.
Does natural mean unheated?
No. Natural describes formation. Treatment is a separate question, so request clear disclosure.
Further reading
Explore with us in Singapore
Explore Sapphire and compare individual pieces with our team. Tell us the colours you enjoy, your intended use and the budget you are comfortable with.