Gemstones of the World: Newly Revised Fifth Edition

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Nassau, Kurt (1990). "Synthetic Gem Materials in the 1980s" (PDF). Gems & Gemology. 26 (1): 50–63. doi: 10.5741/GEMS.26.1.50. Archived (PDF) from the original on November 1, 2021 . Retrieved April 15, 2023.

Gemstones of the world : Schumann, Walter : Free Download Gemstones of the world : Schumann, Walter : Free Download

Nassau, Kurt (1994). Gemstone Enhancement: History, Science and State of the Art (2nded.). Oxford: Butterworth Heinemann. ISBN 9780750617970. OCLC 28889342.Poudretteite was discovered in 1965 at the Poudrette Quarry in Canada and named after the quarry's owners and operators, the Poudrette family. Asian Institute of Gemological Sciences (AIGS), the oldest gemological institute in South East Asia, involved in gemological education and gem testing Lion of Merelani, a square cushion cut tsavorite that weighs 116.76 carats and has 177 facets. It is on display at the Smithsonian Institution.

List of gemstones by species - Wikipedia List of gemstones by species - Wikipedia

Fracture filling has been in use with different gemstones such as diamonds, emeralds, and sapphires. In 2006 "glass-filled rubies" received publicity. Rubies over 10 carats (2g) with large fractures were filled with lead glass, thus dramatically improving the appearance (of larger rubies in particular). Such treatments are fairly easy to detect. Gem dealers are aware of the differences between gem laboratories and will make use of the discrepancies to obtain the best possible certificate. [15] Cutting and polishing [ edit ] A diamond cutter in Amsterdam When jewelry containing diamonds is heated for repairs, the diamond should be protected with boric acid; otherwise, the diamond, which is pure carbon, could be burned on the surface or even burned completely up. When jewelry containing sapphires or rubies is heated, those stones should not be coated with boric acid (which can etch the surface) or any other substance. They do not have to be protected from burning, like a diamond (although the stones do need to be protected from heat stress fracture by immersing the part of the jewelry with stones in the water when metal parts are heated).Access-restricted-item true Addeddate 2021-12-15 08:06:03 Autocrop_version 0.0.5_books-20210916-0.1 Boxid IA40308601 Camera Sony Alpha-A6300 (Control) Collection_set printdisabled External-identifier Prior to development of synthesising processes the alternatives on the market to natural gemstones were imitations or fake. It was in 1837 that the first successful synthesis of ruby occurred. [43] French chemist Marc Gaudin managed to produce small crystals of ruby from melting together potassium aluminium sulphate and potassium chromate through what would later be known as the flux melt process. [44] Following this, another French chemist Fremy was able to grow large quantities of small ruby crystals using a lead flux. [45] Jadeite ranks near the top of a list of one of the most valuable gemstones in the world. This gemstone is jade's most expensive, most beautiful variety. Since this deep green translucentgem is significantly rarer than other types of jade, it is worth much more. Today the gemstone trade no longer makes such a distinction. [15] Many gemstones are used in even the most expensive jewelry, depending on the brand-name of the designer, fashion trends, market supply, treatments, etc. Nevertheless, diamonds, rubies, sapphires, and emeralds still have a reputation that exceeds those of other gemstones. [16] Gachala Emerald". National Museum of Natural History. Smithsonian Institution. 2017 . Retrieved February 8, 2017.