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
Yttrium aluminium garnet has low heat sensitivity. As a synthetic gemstone YAG has numerous varietal and trade names, as well as a number of misnomers. Synonymous names include: "alexite", "amamite", "circolite", "dia-bud", "diamite", "diamogem", "diamonair", "diamone", "diamonique", "diamonite", "diamonte", "di'yag", "geminair", "gemonair", "kimberly", "Linde simulated diamond", "nier-gem", "regalair", "replique", "somerset", "triamond", "YAIG", and "yttrium garnet". Production for the gem trade decreased after the introduction of synthetic cubic zirconia; there was little production. Some demand exists as synthetic garnet, and for designs where the very high refractive index of cubic zirconia is not desirable. Neodymium-doped YAG (Nd:YAG) was developed in the early 1960s, and