Gems by James: August Birthstone is Peridot

Posted by Greg Magnus on August 4, 2010 at 16:43 pm

The birthstone for August is Peridot.

A transparent yellowish-green Magnesium/Iron Silicate, Peridot is a gem variety of the mineral Chrysolite or Olivine. Peridot ranges in color from light yellow-green, olive green and brownish green. The intensity and tint of the green depends on the crystal’s iron content. The most valuable gem is the dark-olive green color. Tinges of brown or visible flaws greatly diminish the gems value.

Olivine, of which peridot is a type, is a common mineral in mafic and ultramafic rocks, and it is often found in lavas and in peridotite xenoliths of the mantle, which lavas carry to the surface; but gem quality peridot only occurs in a fraction of these settings. In general, Olivine is a very abundant mineral but gem quality peridot is rather rare.

In the U.S., Peridot olivine is mined in North Carolina, Arizona on the San Carlos Reservation, Hawaii, Nevada, and New Mexico. And, it is also mined in Australia, Brazil, China, Kenya, Mexico, Myanmar (Burma), Norway, Pakistan, Saudi Arabia, South Africa, Sri Lanka, and Tanzania.

NOTE: Peridot can be special ordered from Gems by James. Please contact us for additional details.