Hello August and hello to Peridot as this month’s beautiful birthstone! Peridot, also known as Olivine, is the most affordable untreated green gemstone in the market. The attractive yellowish green hues are caused by iron, which is part of the gems chemical composition. Formed deep within the earths mantle, this gem often occurs in volcanic rocks called basalts as the force of the eruption blows apart the magma brought to the surface and separates the olivine from the rest of the ejectamenta. Currently the Kilauea volcano of Hawaii has been found to have been essentially “raining” olivine from this process as people are finding small green gemstones in the surrounding areas.