August Birthstone: Peridot Jewelry

Peridot is the primary August birthstone. Spinel was added as an alternative in 2016, and sardonyx appears in older traditional lists.

Peridot is the gem variety of the mineral olivine, and it is always a yellowish-green - the only major gemstone that occurs in just one colour.

It has a long history: peridot was mined on the Egyptian island of Zabargad for thousands of years, and some historians believe stones described as emeralds in antiquity were in fact peridot.

Because the iron that produces its green is part of the mineral's own chemical composition rather than a trace impurity that happens to be present.

In most gemstones colour comes from trace elements - remove them and the stone is colourless. In peridot the colouring element is structural, so every peridot is green.

The green always carries a yellow component for the same reason. A pure green with no yellow in it is a different stone.

It sits at 6.5 to 7 on the Mohs scale, which is toward the softer end of the stones people wear regularly, and it is somewhat brittle as well.

That makes the setting a genuine decision. A bezel or a lower-profile design protects the stone meaningfully and is the sensible choice for a peridot ring worn often.

As a pendant or in earrings, peridot needs no special consideration at all - those pieces take a small fraction of the impact a ring does.

Usually not. Peridot is one of the few coloured stones commonly sold exactly as it formed, without heating, irradiation or filling.

Occasionally a stone with fractures reaching the surface is filled to improve its appearance, and that would be disclosed on the listing.

As a species, peridot generally does not need enhancement to show well, which is unusual among coloured gems.

That is double refraction, and it is a real optical property of the mineral rather than a fault. Light entering peridot splits into two rays travelling at slightly different speeds.

In larger stones, looking through the table at the right angle can make the back facets appear doubled.

Gemmologists use this to identify peridot on sight. It does not affect the beauty or the durability of the stone.

Yellow gold is the traditional pairing and picks up the warm yellow-green of the stone, making it read richer and more classical.

White gold and platinum give the green a cooler, cleaner background, which pushes it toward the pure green end and reads as more contemporary.

Rose gold sets warm pink metal against green, a deliberate complementary contrast that is striking rather than subtle. All three are used across this collection.

Larger stones generally show a deeper, purer green, since colour intensity increases with the depth of material light passes through. Small peridots tend to read lighter and more yellow.

Sizes are given in millimetres rather than carat weight, because millimetres describe what the wearer actually sees.

For everyday earrings and a discreet pendant, small stones are perfectly satisfactory. The size argument matters most where the stone is meant to be the focus of the piece.

Yes - peridot is more sensitive to acids than most gemstones, and household cleaning products can etch its surface with prolonged contact.

It is also sensitive to sudden temperature change, which is why ultrasonic and steam cleaners should be avoided entirely.

Warm water, mild soap and a soft brush are all it needs. Taking a peridot ring off before cleaning the house is genuinely worth doing.

They are different minerals entirely. Peridot is olivine, coloured by structural iron, and always yellowish-green. Emerald is beryl, coloured by chromium or vanadium, and a bluer, deeper green.

They also behave differently. Emerald is harder at 7.5 to 8 but is heavily included and commonly oil-filled. Peridot is softer at 6.5 to 7 but usually cleaner and typically untreated.

The colours are distinguishable once you have seen both: peridot's warm olive green is quite unlike emerald's cooler, more saturated one.

Warm water, a little mild soap and a soft brush, then rinse and dry with a soft cloth. Nothing more elaborate is needed.

Never use an ultrasonic or steam cleaner. Peridot's sensitivity to sudden temperature change makes both a real risk.

Keep it away from household cleaning products and other acidic substances, which can etch the surface, and store it apart from harder stones.