Sapphires are a precious gemstone, a variety of the mineral corundum, consisting of aluminum oxide (α-Al2O3) with trace amounts of elements, such as: iron, titanium, chromium, copper or magnesium. It is typically blue, but natural "fancy" sapphires also occur in yellow, purple, orange, and green colors; "parti sapphires" show two or more colors. The only color corundum stone that the term sapphire is not used for is red, which is called a ruby.[1] Pink colored corundum may be either classified as ruby or sapphire depending on locale. Commonly, natural sapphires are cut and polished into gemstones and worn in jewelry. They also may be created synthetically in laboratories for industrial or decorative purposes in large crystal boules. Because of the remarkable hardness of sapphires – 9 on the Mohs scale (the third hardest mineral, after diamond at 10 and moissanite at 9.5) – sapphires are also used in some non-ornamental applications, such as infraredoptical components, high-durability windows, wristwatch crystals and movement bearings, and very thin electronic wafers, which are used as the insulatingsubstrates of special-purpose solid-state electronics such as integrated circuits and GaN-based blue LEDs.
Abrams, Judith Z. (2012). The Other Talmud--the Yerushalmi: Unlocking the Secrets of the Talmud of Israel for Judaism Today. Jewish Lights Publishing. ISBN9781580234634.- Total pages: 239
BBC News (February 6, 2017). "Queen's Sapphire Jubilee: Gun salutes mark 65 years on the throne". BBC News. Retrieved September 11, 2019.
Christie's (November 19, 2003). "Lot 382: A Magnificent and Historic Sapphire Pendant, By Cartier". Christie's. Retrieved September 11, 2019.
Farges, François; Panczer, Gérard; Benbalagh, Nassima; Riondet, Geoffray (Winter 2015). "The Grand Sapphire of Louis XIV and The Ruspoli Sapphire". Gems & Gemology. 51 (4). Gemological Institute of America. ISSN0016-626X. Retrieved September 11, 2019.
