Peridot

Peridot is the gem form of olivine, a mineral that makes up at least half of the earth's upper mantle. It forms deep underground and is carried to the surface by volcanoes or by the slow movement of the earth's plates. Its colour comes from iron, and it keeps to one family: brownish green, yellowish green and, at its finest, pure green.

Peridot also has one of Africa's oldest gem stories. For centuries the finest stones came from Zabargad, a small island in the Red Sea off the coast of Egypt.

Where the name comes from

The origin of the name is uncertain: GIA traces it to the Arabic faridat, "gem", while the Oxford English Dictionary suggests an old Anglo-Norman word. The ancient Greeks called Zabargad Topazios, and much of what ancient writers called "topaz" was probably peridot.

Beliefs and legends

• The gem of the sun. The ancient Egyptians called peridot the "gem of the sun".
• Against the terrors of the night. People believed it guarded its wearer from nightmares, above all when set in gold, and some strung it on donkey hair and tied it around the left arm to keep evil spirits away.
• An island of snakes. Legend says Zabargad, the Red Sea island where the ancient world's peridot was mined, was overrun with snakes until a pharaoh drove them into the sea.
• Cleopatra's emeralds? Some historians think Cleopatra's famous emeralds may in fact have been peridots.

The colours

• Pure green: the finest and rarest, usually found only in larger stones.
• Yellowish green (lime): the most common peridot colour in jewellery.
• Brownish green: worth less.

Treatments, honestly

Peridot is rarely treated, and GIA knows of no peridot that is heated to improve it. Like any gem, a peridot may have small fractures. We tell you what we know about each stone before you buy it.

How to judge a peridot

• Colour first: a saturated pure green with no brown.
• Clarity: the best are clean to the eye. Disc-shaped "lily pad" inclusions are common; dark mineral crystals lower the value.
• Size: small peridots are inexpensive; fine stones are generally above ten carats.

Caring for your peridot

Peridot is 6.5 to 7 on the Mohs scale with fair to good toughness. Protect it from scratches and hard knocks, which makes it ideal for pendants and earrings, and fine in rings worn with care. Clean it only in warm soapy water: no ultrasonic or steam. Avoid sudden changes of temperature and acids; even acidic perspiration can dull it over time.

At a glance

Mineral	Olivine (magnesium-iron silicate), gem variety
Hardness	6.5 – 7 Mohs
Colours	Yellowish green to pure green; brownish green
From	Zabargad, Egypt (historic); Tanzania; Pakistan, Myanmar, Arizona, China
Treatments	Rarely treated; none known to be heated
Care	Warm soapy water only. No ultrasonic, steam, acids or sudden heat