Sapphire is the hardest coloured stone we work with, second only to diamond, which is what makes it genuinely suitable for an engagement ring rather than an occasional piece. It resists scratching, holds a polish, and survives the sort of daily wear that would damage a softer gemstone.This collection includes the Nefertiti 5.04ct Burma sapphire cluster ring, a stone from the origin most prized by collectors, alongside Elahera, named for the Sri Lankan gem field. Chelsea, Harper, Isabella, Marseille and Toulon carry sapphires in halo and cluster settings, and the range extends to earrings including the 1.20ct blue sapphire and diamond clover design and the square sapphire studs.Most people picture cornflower blue, and that remains the classic, but sapphire occurs in almost every colour except red, where the same mineral is called ruby instead. Pink, yellow, green and the rare padparadscha are all sapphire. Origin matters to value as much as colour does. Burma, Kashmir and Ceylon stones command a premium, and heat treatment, which is common and accepted, affects price considerably.Sapphire is also the September birthstone and the traditional gift for a forty fifth anniversary. Our buyer guide to sapphire covers origin, treatment and what to look for, and gemstone guides compares it with the other coloured stones. For a particular stone that is not shown here, our bespoke service can source it.