Gemstone value of the stone. Some treatments are used widely because the resulting gem is stable, while others are not accepted most commonly because the gem color is unstable and may revert to the original tone. Heat can improve gemstone color or clarity. The heating process has been well known to gem miners and cutters for centuries, and in many stone types heating is a common practice. Most citrine is made by heating amethyst, and partial heating with a strong gradient results in “ametrine” – a stone partly amethyst and partly citrine. Aquamarine is often heated to remove yellow tones, or
Carbuncle (gemstone) 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 English King James translation is a rendering of the Hebrew Masoretic text (Old Testament) and Greek Textus Receptus (New Testament). "Carbunculus" is a word used in Latin 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