Peridot Gemstone
Peridot Gemstone
Peridot Gemology
Species: olivine
Colour: Yellow-green, olive-green, brownish
Chemical composition: (Mg,Fe)2SiO4 magnesium iron silicate
Crystal system: Orthorhombic; short compact prisms, vertically striated
Hardness: 6.5-7 (Mohs scale)
Specific gravity: 3.28 - 3.48
Refractive index: 1.650 -1.703
Birefringence: +0.036 to +0.038
Colour of streak: White
Absorption spectrum: 497, 495, 493, 473, 453
Fluorescence: None

 

Origin:

U.S.A. (most notably Arizona), Australia, Brazil, China, Kenya, Mexico, Myanmar (Burma), Norway, Pakistan, South Africa, Sri Lanka, Saudi Arabia and Tanzania.

The beauty of Peridot the gem form of the mineral olivine, is a result of extreme conditions. Peridot is found in the rocks created by volcanoes and even in meteors that fall to earth. A few samples of extraterrestrial Peridot have even been faceted into gems. Peridot is formed deep within the earth under tremendous heat and pressure.

The fresh lime green of Peridot is its distinctive signature.  Peridot is a green gemstone that is as popular for jewellery today as it was in the past. It has been found in ruins of ancient Egypt and Greece and was often called the evening emerald by ancient Romans, who noticed that its green colour shone even more vividly in lamplight, making it resemble deep green emeralds. Most ancient Peridot probably came from the Red Sea island of St. Johns, which produced highly prized dark-green Peridot.

While emeralds are usually the most popular gemstones that come in green, Peridot is considered the “evening emerald” for its olive tinge and more subtle hue.  While all types of jewellery can be made from Peridot, because of the stone's softness, rings should be worn with care.  If you are looking for a less known, but extremely beautiful rare green gemstone, you can’t do much better than Peridot.

Colour

Peridot Gemstone

Peridot is one of the few gemstones that come in only one colour. The depth of green depends on how much iron is contained in the crystal structure, and varies from yellow-green to olive to brownish green. The slightly golden shimmering green variety is an ideal colour to complement a light summertime outfit. Vivid lime-green Peridot with no olive tones is most popular. The fresh lime green of Peridot is its distinctive signature.

The colour of most gems is caused by traces of other elements but the colour of Peridot is an integral part of its structure. If you love citrus tones or earth tones, you'll find that Peridot is an integral part of your jewellery wardrobe. Its spring green colour also is ideal with sky blue.

Cut

Peridot can be a difficult task for a gem cutter due to the fact that the rough crystals are quite easy to break. It is therefore cut according to its crystal structure and is most commonly found in round, emerald, antique, or oval shaped cuts. Stones that contain numerous or heavy inclusions are generally cut as cabochons. The reason for this is that this shape provides the best possible appearance and helps to disguise inclusions.

Treatments

Occasionally Peridotsare enhanced with colourless oils or resins which reduce the visibility of the inclusions and improve the clarity of the stone. It is also known to occasionally improve the colour.