Carbuncle (gemstone) used by the Greek to translate the Hebrew נֹפֶךְ ("nōphek") in two of its four occurrences in the Old Testament. The etymology of the Hebrew term is uncertain, though Koehler-Baumgartner suggests a connection to פּוּךְ ("phook"), used in the Old Testament as a term for eye makeup, and probably implying a colored powder most likely made from a crushed mineral. For נֹפֶךְ ("nōphek") itself they suggest the gloss "semi-precious stone" (of uncertain color). Carbuncle (gemstone) A carbuncle is any red gemstone, most often a red garnet. The word occurs in four places in many English translations of the Bible. The
Gadolinium gallium garnet Gadolinium gallium garnet Gadolinium Gallium Garnet (GGG, ) is a synthetic crystalline material of the garnet group, with good mechanical, thermal, and optical properties. It is typically colorless. It has a cubic lattice, a density of 7.08 g/cm and its Mohs hardness is variously noted as 6.5 and 7.5. Its crystals are produced with the Czochralski method. During production, various dopants can be added for colour modification. The material is also used in fabrication of various optical components and as a substrate material for magneto–optical films (magnetic bubble memory). It also finds use in jewelry as a diamond simulant. GGG