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JewelryWiki/Gemstones/Peridot

Peridot

OlivineJewelryWiki Editorial·3 sources·Reviewed 2026-07-31
Peridot specimen
Peridot specimen. Robert M. Lavinsky, CC BY-SA 3.0 · Wikimedia Commons

Notably high double refraction, which gives facet edges a visible doubled appearance under magnification.

Properties

PropertyValueAuthority
Mohs hardness6½–7 [1]—
Refractive index1.650–1.703 [1]—
Specific gravity3.28–4.39 [1]—
Crystal systemOrthorhombic [3]
Read from the species article, Olivine.
—
Birthstone monthAugust — shares August with spinel, which Jewelers of America and AGTA added in 2016. [2]—

Sources

  1. International Gem Society — reference charts (Mohs hardness, specific gravity, refractive index) — International Gem Society (IGS reference charts)
  2. Jewelers of America — Birthstones — Jewelers of America (Jewelers of America, Birthstones)
  3. Wikipedia — mineral article infoboxes (crystal system) — Wikipedia contributors (Wikipedia mineral infoboxes)