Birthstone for August: Peridot.

Green-Yellow · Strength, healing, peace

Overview & Meaning

August celebrates the warm golden days of late summer with peridot, a radiant, yellowish-green gemstone that is one of the few minerals born directly within the molten crucible of the Earth's upper mantle. Known to the ancient Egyptians as the 'Gem of the Sun,' peridot’s vibrant olive-to-lime color remains brilliantly constant day or night, earning it the classical moniker 'evening emerald.'

August is enriched by two remarkable companion birthstones: spinel—celebrated for its astonishing brilliance and historical standing in royal crown jewels—and sardonyx, the ancient banded birthstone of courage and victory. In June 2016, the American Gem Trade Association and Jewelers of America officially welcomed spinel to the August roster, offering an exquisite palette spanning ruby-red, cobalt-blue, and violet. Together, this trio signifies radiant cheerfulness, protective fortitude, and creative vitality.

Mineralogical & Geological Profile

Peridot

Chemical Formula

(Mg,Fe)2SiO4 (Forsterite-rich Olivine)

Mineral Species / Class

Olivine (Peridot) / Oxide (Spinel) / Chalcedony (Sardonyx)

Mohs Hardness

6.5 – 7.0 (Peridot) / 8.0 (Spinel) / 6.5 – 7.0 (Sardonyx)

Crystal System

Orthorhombic (Peridot) / Isometric (Spinel)

Geological Formation & Origin

Unlike most gemstones that form in the Earth's crust, peridot crystallizes 100 to 400 kilometers below the surface within the upper mantle's peridotite rock, carried upward by basaltic lavas or xenoliths. It is also found within extraterrestrial pallasite meteorites, dating to the birth of our solar system 4.5 billion years ago. Its green color is idiochromatic—caused by essential iron inherent to its chemical formula, ensuring natural green hues without artificial irradiation.

History, Lore & Symbolism

The ancient Egyptian island of Zabargad (Topazios / St. John’s Island) in the Red Sea was the earliest recorded source of peridot, mined under heavy royal guard from at least 300 BCE. Historians believe many of Cleopatra’s famous 'emeralds' were actually fine Red Sea peridots. Spinel possesses an equally legendary history: the celebrated 170-carat 'Black Prince’s Ruby' set in the British Imperial State Crown—gifted to Edward the Black Prince in 1367—is actually an uncut crimson spinel. Sardonyx, meanwhile, was worn by Roman soldiers carved with the image of Mars to inspire fearless battlefield courage.

Durability, Care & Cleaning

Peridot measures 6.5 to 7.0 on the Mohs scale, requiring mindful care against harsh scratches, acid erosion, and rapid temperature changes. Never use ultrasonic or steam cleaners on peridot; wash gently with lukewarm soapy water and a soft cloth. In contrast, August’s companion stone spinel ranks at a robust 8.0 on the Mohs scale, offering excellent resistance to daily scratches and standard ultrasonic cleaning.

Frequently Asked Questions

Q1 Why was spinel added to August in 2016?

In June 2016, the American Gem Trade Association and Jewelers of America officially added spinel to the August lineup to provide a durable (8.0 Mohs), highly brilliant gemstone with an array of vibrant colors, joining peridot and sardonyx.

Q2 Did peridot really come from meteorites?

Yes! While most commercial peridot is mined from volcanic mantle xenoliths on Earth (such as San Carlos, Arizona), gem-quality olivine crystals also arrive in pallasite meteorites that formed in space during the early accretion of the solar system.