A carbuncle/ˈkɑːrbʌŋkəl/ is any red gemstone, most often a red garnet. The word occurs in four places in many English translations of the Bible. The English translation is a rendering of the Vulgate's Latincarbunculus, a word used for a small coal (or charcoal), and also for any of a number of precious or semi-precious stones, especially those of a red color.Jerome apparently chose the term because of its similarity in meaning to the Septuagint's ἄνθραξ (anthrax meaning coal), which was in turn 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 makup, 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).
Isaiah 54:12 uses carbuncle to convey the value of the Lord's blessing [and promise to] His faithful barren woman servant: (KJV Is 54:1) "Sing, O barren, thou that didst not bear, and cry aloud, thou that didst not travail with child;") Her husband and Maker is God, "Thy Maker is thine husband." (Is 54:5 KJV)
"And I will make thy her windows of agates, and thy her gates of carbuncles, and all thy her borders of pleasant stones."