By Chisom Ibemere
Hypersthene is known as a rock-forming inosilicate mineral which belongs to the group of orthorhombic pyroxenes. It basically occurs in igneous and metamorphic rocks and also in stony and iron meteorites. Enstatite and Ferrosilite had been used to categorize this minerals abandoning the normal term for it. It produces a solid solution series with the enstatite and ferrosilite mineral.
Enstatite in its pure state contains no iron, while ferrosilite in its pure state has no magnesium. Hypersthene is named when a significant amount of the two elements are present. Enstatite is a stable mineral at atmospheric pressure while ferrosilite is only stable at high pressure which decomposes into quartz and fayalite at atmospheric pressure unless stabilized by magnesium or other impurities.
Hypersthene has grey, brown, or green colours with a vitreous to pearly lustre. It exhibits a strong pleochroism with a hardness of 5–6, and the specific gravity of 3.4–3.9. It shows a brilliant copper-red metallic sheen with the same origin as the bronzy sheen of bronzite.
The word “hypersthene” is gotten from the Greek words hyper and stonos that depicts “over strength”. Its major application is in the jewellery industry and in craft. Hypersthene gemstones are found in Adirondack Mountains of New York and in Labrador and Quebec, Canada.
