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
Gemstone irradiation coloring of the diamond's surface. Only high-energy radiation such as gamma ray or neutron can produce fully saturated body colors, and the sources of these types of radiation are rare in nature, which necessitates the artificial treatment in jewelry industry. Irradiation, particularly when done in a nuclear reactor, can make gemstones slightly radioactive, so they are typically set aside for a couple of months to allow any residual radioactivity to decay. The first documented artificially irradiated gemstone was created by English chemist Sir William Crookes in 1905, by burying a diamond in powdered radium bromide. After having been kept there