Peridot

July 19, 2020

When I see a juicy, fresh, green peridot, I feel my eyes widen and a warm glow over my whole body. Whether it is faceted, cabochon or sitting patiently in a slice of Pallasite meteorite, I simply feel instant happiness and gratitude. The ancient Egyptians felt this way too, referring to this green mineral as the ‘gem of the sun’; they too felt the warm glow of the sun’s energy through the vivid, green glimmer. 

The birthstone of August, peridot is the gem variety of the mineral olivine, which is a common mineral sourced from volcanoes. Generally, a well-known gemstone, peridot is a silicate mineral with the formula (Mg, Fe) SiO although has low silica content. Peridot sits between its two end members, the magnesium mineral forsterite (Mg, SiO) and the iron mineral Fayalite (Fe, SiO). The colour of peridot is determined by the varying amounts of magnesium and iron in its composition and colours can vary from a golden yellow, vivid lime through to a dark olive/brown. The highest grade of peridot is said to be a pure grass green but mostly commercially available peridot has a yellowish hue.

Unlike many other gemstones, there are no known treatment that enhance the colour or clarity or peridot. What you see if what you get, however glass and cubic zirconia imitation do exist and they are becoming more and more present in the retail market. Peridot can be found in excellent eye-clean quality although their inclusions are unique and can, in my opinion, add to their allure. ‘Lily pads’ are the most commonly seen and are noted as a diagnostic inclusion of peridot. They are described as a round stress-fissure surrounding a small black chromite crystal (sometimes liquid or gas filled). You may also discover healed fractures, occasionally with an iridescent sheen, and small rounded negative crystals that can produce a glittery effect.

Known as being the stone of strength and regeneration these traits certainly come into play when we learn that peridot is formed in the earth’s mantle (thousands of kilometres deeps) and carried to the surface in lava during volcanic activity. In fact, 50% of the earth’s mantle is comprised of olivine and other high-pressured structural variants. Due to peridot’s high iron and magnesium content it is thought that pallasite meteorites and also formed within the mantle of asteroids and exposure to high temperatures would have allowed the mineral constituents within to recrystallise forming the peridot crystals. Peridot is also very dense, crystallising at extremely high temperatures compared to other minerals, another factor to consider whilst imagining crystals surviving a meteoric impact!

The dense nature of peridot results in a strong birefringence, which refers to a stone double refraction of light. As a single ray of white light enters a doubly refracting gemstone it splits into two rays. Both rays travel at different velocities and in the case of peridot there is a great difference between these two rays. The results can allow you to see double when peering into a cut gemstone; back facets and inclusions may appear to have cloned themselves thanks to this optical phenomenon. Another great party trick of peridot is dispersion, the more appealing term being ‘brilliance’, a quality the Ancient Egyptians no double admired as well.

Deposits of peridot have been found all over the world with most stones hailing from Pakistan, Myanmar, Arizona and Australia. In the 4th century BC an ancient naturalist Pliny the Elder discovered peridot on a small Egyptian island in the red sea which he named the stone ‘topazos’ and the island and this is where the ancient ehyptians were thought to have mined from. This island of Topazos is now known as St John’s Island or Zabargad. Historians also believe that Cleopatra’s famous emerald collection might actually have been peridot, with peridot mining on Topazios beginning around 300 BC. Furthermore, the ancient Greeks and Romans also used peridot in their rings, pendants as they believed it bestowed nobility.

Recently, Made In Earth has been sourcing peridot from Afghanistan with stones presenting a softer shade of green. Bunny Bedi, owner and director at Made In Earth, talks about his experiences with peridot.

“The price of peridot is one that keeps on climbing! We try to keep our prices at a certain mid-range level but peridot has pushed the limits the last few years. Stones over 8mm are particularly hard to find at fair prices, as crystals with good clarity are rate in this size. We’ve always had deep green stones from Pakistan, and they’ve always been my favourite, but recently I’ve discovered a few small parcels of paler stones from Afghanistan. Their delicate colour has had interest from our clients.”

If you are looking to match yourself with a noble and ancient stone which dates back to Ancient Egyptian times than peridot is the stone for you.  Worshipped like the sun throughout the ages and likely to do so forever more, we can say that peridot will maintain its cult-like following for many years to come.


Become part of the family