Vietnam is an important source of peridot for the international gem market. Gemological and geochemical characteristics of Vietnamese peridot from the Central Highlands are similar to those noted for other localities originating from xenoliths in alkaline basalts. Thi s peridot was derived from a spinel lherzolite source and appeared to form at temperatures between 910° and 980°C and an assumed pressure of 2.0 ± 0.5 GPa, corresponding to a depth of around 60 km. Peridot is a yellowish green to green gem variety of the mineral olivine. It is found as nodules in igneous rocks, occasionally as crystals in veins (in Myanmar and Pakistan) or inside meteorites. The main sources are peridotite xenoliths in alkaline basalts and serpentinized dunites (Shen et al., 2011). Commercially important sources are Zabargad, Egypt; San Carlos, Arizona (United States); Myanmar; China; Kohistan, Pakistan; Vietnam; Ethiopia; and Tanzania. Many studies have focused on the characteristics of peridot...
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