Peridot, a gemstone celebrated for its distinctive green hue, is a variety of the mineral olivine. Its color ranges from yellowish-green to olive-green, with the intensity determined by its iron content. This transparent gem has captivated people for centuries, used in ancient jewelry and as a believed protective talisman.
Primary Global Sources
The United States stands as a significant global source of peridot, primarily from deposits in Arizona, known for its vibrant, grassy green coloration. Myanmar, historically known as Burma, also yields fine quality peridot, particularly renowned for its deep, rich green color and clarity.
Pakistan has emerged as another important producer, known for providing large, high-quality peridot crystals with a distinctive deep green hue and transparency from its Suppat region. China has become a substantial supplier, particularly from areas near the Tibetan Plateau. Other notable countries contributing to peridot production include Vietnam, Tanzania, and Australia.
Significant Mining Locations
Within the United States, the San Carlos Apache Indian Reservation in Arizona is the most productive peridot locality in the world, supplying an estimated 80% to 95% of the world’s commercial quality peridot. The peridot occurs as individual grains and aggregates within basalt flows, forming areas like Peridot Mesa.
In Myanmar, the Mogok Valley is a well-known area for high-quality peridot, with specific mines located in the Pyaung-Gaung, Htin-Shu Taung, and Bernard-Myo areas. Pyaung-Gaung peridot is prized for its attractive deep olive green color and can be found in large sizes. Pakistan’s Suppatt region, particularly in the Himalayan mountains, is recognized for producing large and transparent peridots.
Methods of Extraction
Peridot is typically extracted from the Earth through various mining methods, often depending on its geological occurrence. Many deposits are found as irregular nodules within lava flows. Miners often target volcanic regions or alluvial deposits, where gemstones have been naturally carried by water erosion. Methods can range from large-scale open-pit mining to more localized open pits or even tunnels.
Once the peridot-bearing rock is extracted, it is transported for processing. The extracted material is then sorted and graded based on factors such as color, clarity, and size, before being prepared for cutting into finished gemstones.
Geological Origins
Peridot forms deep within the Earth’s mantle, specifically in the upper mantle layer, at depths typically ranging from 20 to 55 miles. It is one of only two gems, alongside diamonds, that forms in the mantle rather than the Earth’s crust. The crystals are composed of magnesium iron silicate.
These mantle-formed peridot crystals are brought to the surface through volcanic activity or tectonic processes. They are commonly found in silica-deficient rocks such as volcanic basalt and other mafic igneous rocks, which are rich in iron and magnesium. As magma rises and cools, peridot crystals can become trapped within the solidifying rock. While most terrestrial peridot originates from volcanic activity, the gem has also been discovered in rare pallasite meteorites.