Magnesium-rich member of the pyrope-almandine series. The name comes from the Green pyropos, meaning “fiery,” and is therefore similar to the Latin name carbunculus (small coal or ember), attributed to all red transparent stones. Its red color, sometimes very bright, is due to small quantities of chrome in the crystal structure.

Appearance Usually bright red, pyrope can be a much less attractive brick or dark red. It can be perfectly transparent, but this feature is less visible in dark specimens. lt is either made into fairly convex cabochons, like almandine garnet, or faceted, with an oval or round mixed cut or, more rarely, a step cut. The faceted gems have good luster, rather less obvious in cabochons. The most valuable types are, of course, the transparent ones with the brightest red color. Pyrope is relatively common, although less so than almandine. Very large stones, up to several hundred carats, have been found; but these are rare and are found in museums and famous collections.

Distinctive features Pyrope is singly refractive, but sometimes displays anomalous patches of birefringence and has a luster comparable to that of ruby and spinel. it is distinguished from the former by a lack of pleochroism and the fact that it does not turn bright red in strong light; but lt can only be distinguished from the latter by measuring its physical characteristics. These are, however, somewhat variable, as iron is inevitably present, due to its isomorphic relationship with almandine. it is called pyrope when the density is between 3.65 and 3.87 g/cma and the refractive index is between 1.730 and 1.751. (Stones with higher densities and refractive indices are called pyrope-almandine and then almandine.) The hardness is 7 or a little more.

Occurrence in the latter half of the nineteenth century, most pyrope came from Bohemia, where it is still found today. The main sources nowadays, however, are South Africa, Zimbabwe, Tanzania, the United States, Mexico, Brazil, Argentina, and Australia. -

Value It is of quite low value as secondary gems go,probably due to its abundance. The darkest specimens, which are the most common, are worth very little. While even in early times pyrope could be distinguished from ruby because of its relative softness, it was more highly valued then than it is today, probably because of its color.

Simulants and synthetics Formerly, when it was more highly prized, pyrope was imitated by glass, which-can lock very similar, but does not have the same hardness. It is not produced synthetically.