Enstatite is magnesium-containing silicate, which is found in a variety of brownish, greenish and/or yellowish hues. Due to the mineral's relatively low hardness and the rarity of facetable transparent raw material, it is generally regarded as being a more of a collector's stone than something you are likely to find in the mass market.
However, an opaque brown variety called bronzite is commonly fashioned into beads and carvings, as well as often being encountered in irregular tumbled forms within necklaces and bracelets. This material has a very distinctive appearance, with fine films of separated iron oxide displaying a somewhat reflective sub-metallic luster.
In addition, the presence of fine needle-like inclusions within some enstatite crystals will cause a well-defined cat's eye effect to be displayed when the stone is cut en cabochon.