Peridot – the transparent gem variety of olivine
Appearance & Properties
Peridot is the transparent gem variety of olivine, a magnesium- and iron-rich mineral. Its colour ranges from yellow-green and olive to a more vivid, slightly brownish green; unlike many gems, it is not usually blue or pure emerald green. Iron is chiefly responsible for the colour. Fine stones can be transparent, while inclusions may appear as tiny dark crystals, fine “lily-pad” structures or liquid-filled cavities. Peridot has noticeable double refraction, so facet edges may look doubled through the stone. With a Mohs hardness of about 6.5–7 and no pronounced cleavage, it is reasonably wearable but can scratch or chip if handled roughly.
History & Discovery
Peridot has been known since antiquity, so it has no single modern discovery date. Ancient Egyptian sources describe mining on Zabargad, an island in the Red Sea, probably from the second millennium BCE onward. The island was later known to classical writers as Topazios, and historical confusion between peridot, emerald and topaz is common. The name “peridot” has an uncertain history; it may be connected with an Arabic term for gem or with older Greek and Latin forms. Mineralogists later recognised that gem peridot belongs to the olivine mineral group; the name olivine refers to its typical olive colour.
Occurrences
The historic island of Zabargad, also called St John’s Island, remains the classic source associated with Egyptian peridot. Important modern material has come from the San Carlos Apache Reservation in Arizona, Pakistan’s Kashmir region, Myanmar, China, Vietnam and parts of East Africa, including Tanzania and Ethiopia. Peridot also occurs in Norway and in volcanic rocks in several other regions. Gem-quality olivine can form deep in Earth’s mantle and reach the surface through volcanic activity. It is also found in pallasites, rare stony-iron meteorites, where olivine crystals are surrounded by metal. A particular stone should not be assigned to any locality without reliable documentation.
Famous Examples & Interesting Facts
A faceted peridot weighing 311.8 carats in the Smithsonian collection in Washington, D.C., is frequently cited among the largest cut examples known. Several green stones in historic European church treasures were once called emeralds and are now considered likely to be peridot, illustrating how difficult gem identification was before modern testing. One of the most intriguing facts is that peridot is found beyond Earth: olivine in pallasite meteorites can be gem quality, although meteorite material is rare and usually handled by specialist collectors. Gem-quality peridot is therefore both an earthly gemstone and, in exceptional circumstances, a visitor from space.
Jewellery & Use
Peridot is commonly fashioned as oval, round, cushion, pear and emerald-style cuts, which show off its lively green colour and double refraction. It is used in rings, earrings, pendants and bracelets, but rings benefit from protective settings because the stone is softer than sapphire or ruby and may chip at exposed corners. Clean it with lukewarm water, mild soap and a soft brush, then dry it carefully. Avoid harsh chemicals, sudden temperature changes, steam and ultrasonic cleaning, especially when inclusions or fractures are present. Most peridot is sold without enhancement, but treated natural material, laboratory-created material and imitations exist; treatment status should be confirmed separately for each stone.
Symbolism, Astrology & Tradition
Peridot is widely recognised as a modern August birthstone and is also commonly associated with the 16th wedding anniversary. In ancient Egyptian symbolism it was linked with the sun and protection, although interpretations of historical texts are not always certain. Some traditions connect it with Leo or Virgo, but zodiac assignments vary by culture and astrology system. Folklore has sometimes called it a protective stone or a charm against envy and nightmares. Modern crystal and esoteric practices may attribute emotional or spiritual benefits to peridot; these are beliefs and symbolic interpretations, not scientifically established effects. Green olivine crystals from Hawaii are also connected in popular tradition with the “tears of Pele.”