While historically, thanks to its vibrant green hue, peridots have often been mistaken for emeralds – this month’s birthstone is a popular jewelry contender and is today considered spectacular in its own right.
What they are
Peridot, also referred to as olivine and chrysolite, is a magnesium iron silicate.
One of the few gemstones that occur in only one color, peridots are generally olive green. The intensity and tint of the hue, does however, depend on the quantity of iron contained in the crystal structure. A peridot’s color can therefore range from yellow to olive and brown to green. The most prized peridot color is dark olive-green.
How they’re made
Olivine, of which peridot is a type, is a common mineral in mafic and ultramafic rocks – a silicate mineral or rock that is rich in magnesium and iron.
Olivine is frequently found in lavas and in peridotite xenoliths of the mantle which lavas carry to the surface, making it – in general – a very abundant mineral. Gem quality peridot, however, only occurs in a fraction of these settings and is therefore rather rare.
Where they’re found
A tiny Egyptian island in the Red Sea – formerly known as St. John and now known as Zabargad – was one of the only ancient sources of peridot. Today this deposit has been totally exhausted and the stone is now mined throughout the globe, most notably in Arizona on the San Carlos Reservation – a significant producer of gem-quality peridot.
Myanmar, China, Afghanistan and Pakistan have also provided exceptional quality peridot with deposits producing large, almost flawless, crystals.
What to look out for
Though beautiful, peridot is not the most durable gemstone. With a lower hardness than other gemstones care must be taken not to store peridot jewelry in places it can be scratched or to bang the stone as it can be chipped. Peridot should also never be steam cleaned or cleaned with ultrasonics.
What do you think of the “other” green stone? Tell us below!