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Main sapphire-producing countries. Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide (α-Al 2 O 3) with trace amounts of elements such as iron, titanium, cobalt, lead, chromium, vanadium, magnesium, boron, and silicon.
National Museum of Natural History, Washington [9] Star of Bombay: Sri Lanka 182 carats (36.4 g) Star Blue-violet National Museum of Natural History, Washington [10] Ruspoli Sapphire: 136.9 carats (27.38 g) [11] Stuart Sapphire: Sri Lanka 104 carats (20.8 g) Blue Tower of London [12] Bismarck Sapphire: Myanmar: 98.56 carats (19.712 g) Table Blue
Fancy sapphires of various colours are also available. In the United States, blue sapphire tends to be the most popular and most affordable of the three major precious gemstones (emerald, ruby, and sapphire). Turquoise Turquoise is found in only a few places on Earth, and the world's largest turquoise-producing region is the southwest United ...
As the Yogo mines were still owned by the English, the United States government could not control those operations, so the mines were little affected by the war, even though industrial sapphires were critical to the war effort. [68] The Yogo Sapphire Mining Corporation of Billings, Montana, was the next company to try to run the English Mine ...
Title page of a printed lapidary by Conrad Gessner of 1565. A lapidary is a text in verse or prose, often a whole book, that describes the physical properties and metaphysical virtues of precious and semi-precious stones, that is to say, a work on gemology. [1]
Examining a pink sapphire under a gemmological microscope. Gemology or gemmology is the science dealing with natural and artificial gemstone materials. It is a specific interdisciplinary branch of mineralogy. Some jewelers (and many non-jewelers) are academically trained gemologists and are qualified to identify and evaluate gems. [1] [2]
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However, the Verneuil process could also be used for the production of other stones, including blue sapphire, which required oxides of iron and titanium to be used in place of chromium oxide, as well as more elaborate ones, such as star sapphires, where titania (titanium dioxide) was added and the boule was kept in the heat longer, allowing ...