A to Z of Gemstones: P: Peridot


Gemstone family: Olivine

Crystal System: Orthorhombic

Moh's scale of hardness: 6.5-7

Lustre: Vitreous

Birthstone: August

About: Peridot is the gem variety of the mineral olivine.  Peridots’ colour range is very limited; they only come in light to dark yellowish greens which are caused by the presence of iron.  Peridots are relatively clean stones but they occasionally have a typical disk-like liquid and gas inclusion known as “lily-pad”.

Origin: The main sources of peridot are: Myanmar, Pakistan, Arizona in the U.S.A. and China.

Use in jewellery: Peridot is suitable only for jewellery that has secure settings to protect the stone from wear.

Treatments, synthetics and imitations: There are no known treatments for peridot and it has not yet been lab synthesised.  Some materials that are commonly used to imitate peridots are: glass, plastic and triplets.