Beyond Diamonds — A Guide to Precious Gemstones

Ruby is red corundum.

Its colour can range from pinkish red through to rich, saturated reds.

Corundum ranks 9 on the Mohs hardness scale, making ruby one of the harder natural gemstones and generally well suited to jewellery.

Sapphire is also corundum.

Blue is the famous one — but sapphires can also be yellow, pink, green, orange, purple and other colours.

This variety makes sapphire enormously versatile in bespoke jewellery.

Emerald is the green variety of beryl.

Unlike diamond, ruby and sapphire, emerald commonly contains visible inclusions and fissures. These characteristics are often part of the visual identity of the stone.

Many emeralds are treated with oils or resins to reduce the appearance of surface-reaching fractures, which is also why cleaning and repair require particular care.

Tanzanite is the blue-to-violet variety of the mineral zoisite.

Its commercial source is confined to a small area of northern Tanzania, giving it an unusual geographic story.

It is beautiful but requires more care than sapphire or ruby, particularly when worn in rings.

Another member of the beryl family.

Aquamarine ranges from pale blue to blue-green and often has wonderful clarity.

Its quieter colour makes it particularly beautiful in pieces where the design itself deserves room to breathe.

Tourmaline isn't one colour.

It's an entire family of possibilities.

Pink, green, blue and beautifully multi-coloured stones can all occur, making tourmaline particularly interesting for one-of-a-kind jewellery.

Opal behaves unlike almost anything else.

Precious opal can show play-of-colour — shifting flashes of colour as the stone or viewing angle changes.

It also needs thoughtful care. Opal is considerably less hard than diamond, ruby or sapphire and should be treated accordingly.

Hardness matters, but it isn't the whole story.

Toughness, cleavage, fractures, treatments and how a piece will actually be worn all influence whether a particular gemstone is suitable for a design.

A stone that's wonderful in earrings may need more protection if it's going into a ring worn every day.

That's part of the design conversation.

If you've fallen in love with a gemstone, bring the idea to us. We'll help you understand how it behaves and design around the stone rather than forcing it into the wrong job.