Peridot, pronounced pair-a-doe, is one of the few gemstones to occur in just one colour, and unlike most other stones, it doesn’t depend on light for its shimmer…
Emerald of the crusaders
Peridot has been mined as a gemstone for an estimated 5000 years. Beads were made by the Egyptians as early as 1580BC, and it was brought back to Western Europe at the end of the Crusades. People in Europe called it the ‘emerald of the crusaders’. Peridot was used in the Middle Ages to adorn church treasures, and it became a popular jewellery choice in Europe during the Baroque period.
Peridot is classed as a forsterite-fayalite mineral from the olivine group of minerals. It is one of the few iodiochromatic (one colour) gems, which derives its colour from the mineral itself and not from other impurities.
It is also unique for having a lustre that isn’t dependent on light – it maintains its brilliant shimmering colour at all times.
Peridot has a hardness of 6.5 - 7 on the Mohs scale, so it is a fairly durable robust stone that can handle normal daily wear and tear.
Green with envy
Peridot is known for being green, but the intensity of colour can vary within the green spectrum depending on how much iron is present in the crystal structure. Hues can vary from pale yellow-green through to olive green.
If chromite crystals are present, they can induce flat stress cracks that resemble water lily leaves.
Strange but true
Pirates in the Middle Ages believed peridot could drive away evil spirits, especially if set in gold. But in order for it to work, the stone had to be pierced, strung on donkey hair and worn on the left arm.
Peridot can been found in very large sizes. A 319-carat peridot is on display in the Smithsonian Museum in Washington; a 192-carat peridot is housed in the Diamond Treasury in Moscow; and a 136-carat stone is on show at the Natural History Museum in London.
Where in the world ?
Peridot can be found in many locations including Africa, Australia, Brazil, Mexico, Pakistan, Sri Lanka, Norway and the US.
To ensure your jewellery remains as dazzling as the day you buy it, see our guide called Cleaning & Care - How to Keep Your Jewellery in Mint Condition.