August Birthstone: Peridot, Spinel and Sardonyx, Explained

The August birthstone is actually three stones: peridot, spinel and sardonyx. Peridot is the bright lime-green one most people know. Spinel is the gem that fooled royal jewellers for centuries. Sardonyx is the striped stone the Romans carved into seals. And here's the best bit: peridot has been found inside meteorites that fell from space.

Why August has three birthstones

Birthstone lists have changed a lot over the centuries. In 1912, American jewellers agreed on one standard list so everyone sold the same stone for the same month. August got sardonyx and peridot. The list has been updated a few times since, and people now just call it the modern list.

Spinel joined in 2016, which makes it one of the newest additions anywhere on the calendar. So August now has three. June does too, and December has at least three. You can see how the rest of the year lines up in our guide to every month's birthstone.

Peridot: the lime-green August birthstone

Peridot is the gem version of a mineral called olivine. It forms deep inside the Earth, in the mantle, and gets carried up to the surface by volcanoes. That's also why it shows up in some meteorites: olivine forms in space rock too.

Its colour comes from iron, and it only comes in green. The shade runs from yellowish lime to a deep olive. Very few gems stick to one colour family like that. GIA's peridot guide covers the science if you want more.

Peridot sits at about 6.5 to 7 on the Mohs hardness scale. That's fine for earrings, necklaces and bracelets, but it can scratch if it's knocked around in a ring every day.

What peridot symbolizes

Peridot is traditionally linked with light, warmth and good luck. The story goes that its glow stays bright even by lamplight, which earned it the nickname "evening emerald". Ancient Egyptians prized it, and some historians think a few of the famous "emeralds" of the ancient world were really peridot.

Today, people use peridot as a cheerful reminder to let go of old grudges and start fresh. It's often linked with the heart and solar plexus chakras, and with Leo and Virgo, the two signs August straddles.

Spinel: the gem that was mistaken for ruby

Spinel is a mineral made of magnesium, aluminium and oxygen. It comes in red, pink, purple, blue and black. It's hard, at about 8 on the Mohs scale, so it wears well.

For centuries, red spinel was confused with ruby. One of the most famous "rubies" in the British crown jewels, the Black Prince's Ruby, turned out to be a spinel. Spinel finally got its own name once gem science could tell the two apart.

Spinel is traditionally linked with fresh energy and keeping going. One honest note: we don't carry spinel at The Rock Space. If you love the idea, a jeweller is the place to look.

Sardonyx: the original August birthstone

Sardonyx is a banded chalcedony. Chalcedony is quartz made of crystals far too small to see. Sardonyx has layers of reddish-brown sard stacked with white or black onyx, which gives it those neat stripes. It sits around 6.5 to 7 on the Mohs scale.

Those stripes made it perfect for carving. The Romans cut sardonyx into cameos and signet seals. It was said that hot wax wouldn't stick to it. The story goes that Roman soldiers wore it for courage in battle. Today people use it as a steady, grounding stone for strength and self-control.

Banded stones like this are sometimes dyed to boost the contrast, so it's always fair to ask. At The Rock Space, treated, dyed and man-made stones are labelled as such.

August zodiac signs and their stones

August is split between two signs:

• Leo runs until about August 22. Bright, warm peridot is a natural fit for the sun-ruled sign. Browse the Leo collection.
• Virgo starts around August 23. Peridot and sardonyx both suit Virgo's practical streak. See the Virgo collection.

Want to know your moon and rising signs too? Our free natal chart works them out from your birth time and place.

Is my peridot real?

Good news: peridot is rarely treated. Most of it comes out of the ground looking green already. The main fake is green glass. A few clues:

• The colour. Real peridot has a slightly oily, yellow-green glow. Glass is often a flatter, brighter green.
• Doubling. Look through a faceted peridot with a magnifier. The back edges often look doubled. Glass doesn't do that.
• Little flaws. Natural peridot often has tiny dark specks or flat "lily pad" shapes inside. Glass has round bubbles instead.

Chip and bead peridot is usually small and a bit uneven. That's normal for natural stone.

Caring for August birthstones

• Rinse and wipe. Warm water, mild soap and a soft cloth work for all three.
• Skip the ultrasonic cleaner. It can stress peridot and loosen strung pieces.
• Avoid sudden heat. Peridot doesn't like big temperature swings.
• Store pieces apart. Spinel is harder than peridot and sardonyx and can scratch them.

August birthstone gift ideas

A birthstone is an easy gift because the hard part, choosing, is already done. A few ideas from the shelf right now:

• Something to wear daily. The peridot chip bracelet is bright, light and easy to stack.
• Fine and delicate. The peridot bead necklace uses tiny 2-3mm beads.
• For makers. The banded onyx (sardonyx) bead strand is matte, round and ready to string.
• Their own design. Pick the stones bead by bead in our Design Your Own Bracelet builder.

See more in the peridot collection. Shopping for other birthdays? See the July birthstone and the September birthstone guides.

Know someone with a August birthday? Make them a free August birthstone card and send it by text or email.

Frequently asked questions

What are the birthstones for August?

Peridot, spinel and sardonyx. Sardonyx and peridot were on the 1912 list, and spinel was added in 2016. Peridot is the one most people think of first.

What is the rarest birthstone?

Alexandrite, a June stone, is the one usually named. Fine natural rubies, emeralds and pearls are also very rare. Of August's three, large clean spinel is the hardest to find.

What does peridot symbolize?

Peridot is traditionally linked with light, warmth and good luck. People use it as a cheerful reminder to let go of old grudges and start fresh.

How much is peridot worth?

Value depends on size, colour and clarity. Small chips and beads are affordable. Large, clean stones with a rich green colour are much rarer and cost far more.

Come say hi

Peridot's green is hard to judge on a screen, so it's worth seeing in person. Visit us at 396 Victoria Street North in Kitchener and hold a few before you choose. Or take the Crystal Quiz if you'd rather start online.