The name natural crystal enstatite is derived from the Greek word enstates, meaning “opponent,” which refers to the gem’s reluctance to be melted by a blowpipe, an early method for determining mineral chemistry. It was first described by German geologist G.A. Kenngott in 1855. Like hypersthene, it is a member of the pyroxene family of minerals, natural crystal enstatite is a magnesium silicate with 1.650-1.673 refractive index. Natural crystal enstatite is from single-chain silicates class with orthorhombic crystal system. Available colors are in white, green, brown, grey, or colorless
With dispersion range between 0.019-0.022 and birefringence between 0.009-0.010, natural crystal enstatite is not well known in the world of natural gemstones and is mainly a collector’s item. The habit is prismatic, layered, and massive. However, it can be found in jewelry as a cat’s eye (cut en cabochon) or faceted in a step cut, usually in pendants or earrings. It is too soft for rings. Natural crystal enstatite crystals with a clear crystal shape are the rarest, and therefore the most valuable. Its luster is vitreous to pearly and the fracture is conchoidal.
Natural crystal enstatite is most often found in metamorphic or igneous rocks and has also been discovered in some meteorites. It forms in the orthorhombic crystal system but its structure changes to a monoclinic symmetry structure (known as clinonatural crystal enstatite) at very high temperatures. The hardness stopped at 5.5 Mohs. Natural crystal enstatite has distinct-in-two-directions cleavage and specific gravity in 3.22-3.28 interval. Bright green natural crystal enstatite (whose color is due to traces of chromium) occurs in South Africa and is known as chrome natural crystal enstatite, which is cut as a gemstone. Greenish brown stones are found in upper Burma (Myanmar), and these exquisite stones often show an excellent cat’s eye effect, with a thin orange to pale brown line on an almost black background. Some colorless stones and grayish cat’s eye specimens are found in Sri Lanka. A deep brown, six-rayed star natural crystal enstatite has been seen in Mysore, India. Natural crystal enstatite is also available in Tanzania, Kenya, Germany, Greenland, and Norway.
