Nephrite Jade Jewelry: The King of all Jades Nephrite is a type of calcium, iron, and magnesium-rich mineral tremolite or actinolite. It is a species of Jade. Broadly, there are mainly two species of Jade. The other species of jade is known as jadeite jade, which is rarer, and is a variety of pyroxene. Nephrite jade generally has mainly grey and green colours, however, it is also found in yellow, black, brown, or white colour. Nephrite jade is a gemstone used in beads, carvings, or cabochon-cut gemstones. It is the official state mineral of Wyoming. Most of the lapidary nephrites are mined in Western Canada.