Hypersthene is a common rock-forming mineral belonging to the group of orthorhombic pyroxenes. The name has now been formally abandoned and enstatite or ferrosilite is preferred. It is found in igneous and some metamorphic rocks as well as in stony and iron meteorites. It forms a solid solution series with the minerals enstatite and ferrosilite, being a mid-way member between the two, and for both of which it is often regarded as a synonym. The chemical formula is (Mg,Fe)Si0₃.

Distinctly developed crystals are rare, the mineral being usually found as foliated masses embedded in the igneous rocks norite, hypersthene-andesite, etc. of which it forms an essential constituent. The coarse-grined labradorite-hypersthene-rock (norite) of the island of Paul off the coast of Labrador has furnished the most typical material; and for this reason the mineral has been known as Labrador hornblende or paulite.

Color is often gray, brown or green, and the luster is usually vitreous to pearly. The pleochroism. is strong, the hardness is 6, and the specific gravity is 3.4 - 3.5. On certain surfaces it displays a brilliant upper-red metallic sheen, or schiller, which has the same origin as the bronzy sheen of bronzite, but is even more pronounced. Like bronzite, it is sometimes cut and polished for ornamental purposes.

The name hypersthene comes from the Greek and means "over strength". It is in allusion to its greater hardness than the amphibole mineral hornblende, a mineral with which it is often confused.