Peridot in Depth
A gem from the mantle
Peridot is gem-quality olivine, a magnesium iron silicate that makes up a large share of the earth's upper mantle. It arrives at the surface in basalt that carried mantle fragments up with it, which means holding peridot is holding material from tens of kilometers down. It also occurs in pallasite meteorites, where olivine crystals sit embedded in nickel-iron, so peridot is one of very few gems found beyond earth.
It is the rare gemstone that comes in exactly one color. Iron in the structure produces green, and the amount of iron only shifts it between yellow-green and olive. There is no blue peridot, no red peridot. Zabargad Island in the Egyptian Red Sea supplied the ancient world, and Arizona's San Carlos Apache lands, Pakistan's Kohistan region, and Myanmar are modern sources.
Historically confused with emerald
A good deal of what old European treasuries recorded as emerald turned out to be peridot. The most cited example is the Three Magi shrine in Cologne Cathedral, whose green stones were long taken for emeralds. Cleopatra's famed emeralds are also widely suspected to have been Zabargad peridot, since that mine was under Egyptian control and true emerald sources were not.
Telling them apart is easy with a loupe. Peridot has strong double refraction, so looking through a faceted stone at the back facets shows them doubled, a fuzzy twinned edge that emerald does not show. Peridot is also softer and much less included.
Handling it properly
Peridot is 6.5 to 7 on Mohs, which sounds fine, but it is more delicate than that number suggests. It is sensitive to acids, including sweat over long periods, so a peridot ring worn constantly loses polish. It is also prone to thermal shock and fractures easily under sudden temperature change.
Never use ultrasonic cleaners on peridot, since stones with inclusions can break outright. Skip steam. Warm soapy water, a soft brush, and a rinse are correct. Keep it away from household chemicals and take rings off before cleaning the kitchen.
Practice and pairings
Peridot is the August birthstone and is linked to Leo and Virgo. Its traditional association is with releasing envy and resentment, which is an oddly specific reputation going back to antiquity, and modern practice keeps that theme of clearing out comparison and letting things go without bitterness.
It works at the heart chakra with a solar plexus link, an unusual pairing that fits the theme of comparison sitting between what you feel and what you want. It combines with citrine for warmth, with rose quartz when the resentment is toward someone close, and with clear quartz to sharpen it. Because good peridot is a real gemstone rather than a tumble, most people own one small set piece rather than a grid's worth.