August Birthstone: Peridot, Spinel & Sardonyx

What is the August birthstone?

August has three modern birthstones: peridot, spinel and sardonyx. Peridot is the long-standing favourite and the one most people picture, but the American Gem Society lists all three, so August babies have real choice. Spinel is the newcomer of the group, added to the official list in 2016 by the American Gem Society and Jewelers of America, which makes it one of the most recent changes to the birthstone calendar. You can see the whole year at a glance on our birthstones guide.

Peridot: August's main stone and how it wears

Peridot is the gem-quality form of the mineral olivine, and it is unusual for coming in only one colour. Every peridot is green; what varies is the shade, from a light yellowish green through a bright lime to a deep olive or bottle green, with the purest grassy greens generally the most prized. That single-colour honesty is part of its charm, and it has a warm, glowing quality under most light.

For durability, peridot is middling. It sits at 6.5 to 7 on the Mohs scale, which is hard enough for pendants, earrings and occasional-wear rings, but the International Gem Society notes it is not as tough as the harder stones and can be scratched or chipped with rough daily wear. It is also sensitive to sudden temperature changes and to acids, so it wants a bit more thought than a ruby or sapphire would. In a ring, a protective setting and sensible habits go a long way. A curious footnote: some peridot has arrived on meteorites, and it is one of very few gems also found in material from space, though the stones in the shop are firmly earthly.

The meaning and history of peridot

Peridot has been mined for thousands of years, most famously on the Egyptian island now called Zabargad in the Red Sea, where it was worked in antiquity. The ancient Egyptians called it the gem of the sun, and it has long been associated with light, warmth and good fortune, which suits its sunny green nicely. Some historians believe certain 'emeralds' in old European treasuries, including pieces linked to Cleopatra, were in fact peridot, since the two green stones were easy to confuse before modern gemmology. Whatever the mix-up, peridot has carried a reputation as a cheerful, protective stone for a very long time.

August's other two stones: spinel and sardonyx

Spinel is the standout addition and, frankly, an underrated gem. It is harder and tougher than peridot, at about 8 on the Mohs scale, and comes in a wide range of colours: red, pink, purple, blue, grey and more. Its red can rival ruby so closely that several famous 'rubies' in royal collections, including the Black Prince's Ruby in the British Imperial State Crown, turned out to be spinel. Because it wears well and is beautiful in its own right, spinel is a smart pick for a ring that will see daily use, and its 2016 addition to the list finally gave it the recognition it deserved.

Sardonyx is the oldest and most understated of the three. It is a banded variety of chalcedony, a form of quartz, with reddish-brown and white layers, and it has been used since antiquity for carved seals and cameos. It sits around 6.5 to 7 on the Mohs scale and takes a warm polish, making it a good choice for signet rings and carved pieces rather than sparkling faceted stones.

Choosing and gifting an August piece

Here's how I'd steer you. If you want the classic August look and a friendly price, peridot is the answer, and because it's only moderately tough I'd favour earrings, a pendant or an occasional-wear ring over an everyday band. If the gift is for someone who wears a ring hard, spinel is the better buy: it is more durable, comes in a lovely range of colours, and still flies under most people's radar, so it feels like a discovery. Sardonyx suits anyone drawn to something classical, especially a carved signet ring with a bit of history behind it. Green sits well against both yellow and white metal, so with peridot the choice is mostly about taste. We cut, set and design all three at our Coquitlam studio, and our goldsmith can match the stone to how it'll be worn. Peridot is also the traditional 16th anniversary stone, so an August commission can mark both a birthday and sixteen years together; our bespoke anniversary pieces page is the place to begin.

Caring for peridot and sardonyx

Peridot needs gentle care. Clean it with warm soapy water and a soft brush, and keep it away from ultrasonic and steam cleaners, which can crack a stone that dislikes sudden heat and vibration. Take a peridot ring off before rough work, store it apart from harder gems so it doesn't get scratched, and keep it away from acids and harsh chemicals. Sardonyx is similarly happy with a soft cloth and mild soapy water and should also skip the machines. Spinel, being harder and tougher, is the easy one of the three and tolerates normal cleaning well. Treated sensibly, all three will keep their looks for years.

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