Shigley, James (2000). "Treated and synthetic gem materials". Current Science. 79 (11): 1566–1571. JSTOR 24104849. It’s unusual to find a gemstone reference that can be used by scientists, jewelers, collectors, and laypeople, but such is this book, complete with color photos of over 2500 gemstones, both finished and in natural state. The volume is heavy for its size because it’s published on high quality glossy paper. As the author warns us, the text is small and in some cases abbreviated and condensed. This is to cram the maximum amount of information into a guidebook that’s quite portable. One interesting note about the photos is that often average specimens, rather than be-all, end-all quality gems are depicted. No space is wasted; even the inside covers show different gemstone cuts and a world map of gemstones respectively. Yet because of clever use of headers, shaded sections, illustrations, and white space, the text never seems cramped. Serendibite was discovered in Sri Lanka by Sunil Palitha Gunasekera in 1902 and named after Serendib, the old Arabic name for Sri Lanka.

GIA Gem Encyclopedia | Complete List Of Gemstones

Heat can either improve or spoil 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 to change green colors into the more desirable blue, or enhance its existing blue color to a deeper blue. [30] Several terms redirect here. For other uses, see Gemstone (disambiguation), Gems (disambiguation), Gem (disambiguation), Jewels (disambiguation),and Precious stone (disambiguation). Following the spectacular success of the first four editions of Gemstones of the World, the revised fifth edition exhibits important updates and a beautiful new cover. All the gemstones ever discovered are treated here in their many variations. More than 1,500 full-color photos showcase each precious and semiprecious stone in both its rough natural state and its polished and cut renditions. Each entry offers complete information on a stone's formation and structure; physical properties and characteristics; and methods of working, cutting, and polishing. Land of the Lustrous is an anime and manga series whose main characters are depicted as humanoid gemstones. Gemstones are often treated to enhance the color or clarity of the stone. In some cases, the treatment applied to the gemstone can also increase its durability. Even though natural gemstones can be transformed using the traditional method of cutting and polishing, other treatment options allow the stone's appearance to be enhanced. [27] Depending on the type and extent of treatment, they can affect the 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. [28] Early history [ edit ]Grandidierite was discovered by Antoine François Alfred Lacroix (1863–1948) in 1902 in Tuléar Province, Madagascar. It was named in honor of the French naturalist and explorer Alfred Grandidier (1836–1912).

Gemstones of the World: Newly Revised Fifth Edition

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]

Jayaraman, A (2000). "A brief overview of gem materials: Natural and synthetic". Current Science. 79 (11): 1555–1565. JSTOR 24104848. Archived from the original on April 15, 2023 . Retrieved April 15, 2023– via JSTOR. In modern times gemstones are identified by gemologists, who describe gems and their characteristics using technical terminology specific to the field of gemology. The first characteristic a gemologist uses to identify a gemstone is its chemical composition. For example, diamonds are made of carbon ( C) and rubies of aluminium oxide ( Al Nearly all tanzanite is heated at low temperatures to remove brown undertones and give a more desirable blue / purple color. [31] A considerable portion of all sapphire and ruby is treated with a variety of heat treatments to improve both color and clarity.