Peridot

Peridot, traditionally considered as ‘semi-precious’, is a fine gem and member of the olivine isomorphic series. Since antiquity, peridot has been valued for its characteristic vivid green colour. 

Peridot is one of the few gemstones that displays a single and consistent colour due to the presence of iron (Fe), which is an essential component of its chemical composition whereas most gems owe their colour to small amounts of chemical elements present as impurities in their structure.

Where can you find the peridot you need?

Pierres de Charmes carries a vast selection of fine quality peridot.  Our collection of well-cut stones includes many different shapes and sizes including calibrated stones. 

Peridot Fact Sheet

Peridot has a vitreous lustre and a moderate hardness of 6.5 on the Mohs scale. Special attention is suggested when wearing peridot jewellery such as rings.

Gemmologists can use many instruments to identify peridot. The iron in peridot’s composition produces a diagnostic absorption spectrum that can be seen using a small portable instrument called a spectroscope.

Magnification often reveals a typical inclusion called a ‘lilypad’ that is actually a tension halo surrounding a chromite crystal.  Peridot’s high birefringence also means that a doubling effect of inclusions or facet junctions can be seen with a loupe or microscope.

Inclusion free material is facetted while more translucent or included material can be fashioned as cabochons.

Producing Countries

Important peridot deposits are found in China, Myanmar, Pakistan, and the United Sates. Peridot is found in very hard host rock material that was transported to the surface by ancient volcanic eruptions. Peridot is rarely found as whole orthorhombic prisms and more commonly found as rounded or broken crystal fragments.

Is peridot treated ?

Peridot is rarely treated however, heavily fractured material can be fracture filled to improve the clarity and durability.  Some very dark peridots can be heat treated to lighten the colour.

Peridot in Jewellery

Peridot’s characteristic colour has made it a popular choice in jewellery.  It’s moderate hardness of 6.5 makes it best suited for pendants or earrings.  However it can also be worn in rings where the choice of setting style provides some protection for the stone.

Peridot is sensitive to acids and contact should be avoided with cosmetic products including perfume and hairspray.

Value and Quality Criteria

Colour is the most important quality criteria for peridot with a rich deep green being the most desirable. Most peridots show slight hints of yellow.  Many peridots in the market are ‘eye-clean’ meaning no inclusions are visible without magnification. Stones with dark or easily visible inclusions will have a significantly lower value.

Size will also have an influence on value and large peridots are rare and will command a premium.

Fun Fact

Some peridot comes from outer space! In fact, peridot has been found in meteorites.

Gem property Chart A [Chart]. (n.d.). In Gemological Institute of America (GIA). 1992

Schumann, W. (2000). Guide des pierres précieuses: Pierres fines et ornementales. Lausanne: Delachaux et Niestlé. p.158

Pér-2. In Cours de base en gemmologie Gem-A. London, 2010

Peridot Quality Factors. (n.d.). Retrieved August 06, 2016, from http://www.gia.edu/peridot-quality-factor

Peridot Description. (n.d.). Retrieved August 06, 2016, from http://www.gia.edu/peridot-description