Gemstones of the World: Newly Revised Fifth Edition

Product Information

The Gem and Jewelry Institute of Thailand (Public Organization) or GIT, Thailand's national institute for gemological research and gem testing, Bangkok [21] 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 ] To produce corundum, a pure aluminium powder is used with different additives to achieve different colors. [44] Hibonite was discovered in 1956 in Madagascar. It was named after the discoverer, French geologist Paul Hibon. Gem quality hibonite has been found only in Myanmar. [53]

Gemstone - Wikipedia Gemstone - Wikipedia

A complete guide to Gemstones". Jewellery Monthly. April 2, 2015. Archived from the original on August 28, 2017.

Cultured, synthetic, or "lab-created" gemstones are not imitations: The bulk mineral and trace coloring elements are the same in both. For example, diamonds, rubies, sapphires, and emeralds have been manufactured in labs that possess chemical and physical characteristics identical to the naturally occurring variety. Synthetic (lab created) corundum, including ruby and sapphire, is very common and costs much less than the natural stones. Small synthetic diamonds have been manufactured in large quantities as industrial abrasives, although larger gem-quality synthetic diamonds are becoming available in multiple carats. [37] A few years later an alternative to flux melt was developed which led to the introduction of what was labeled "reconstructed ruby" to the market. Reconstructed ruby was sold as a process which produced larger rubies from melting together bits of natural ruby. [46] In later attempts to recreate this process it was found to not be possible and is believed reconstructed rubies were most likely created using a multi-step method of melting of ruby powder. [44] The book is written for people who have no special training in geology or gemology. It explains how and where gems are found, how gems are mined, how they are cut, how some of them are treated, their physical properties, and how they are used by people. We use this book for learning and reference weekly. If we could have just one book about gems, this would be it! 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.

GIA Gem Encyclopaedia | Complete List Of Gemstones

Bleaching [ edit ] Pearls are a gemstone that is commonly treated with hydrogen peroxide to remove unwanted colours The flame fusion process is completed in a Verneuil furnace. The furnace consists of an inverted blowpipe burner which produces an extremely hot oxyhydrogen flame, a powder dispenser, and a ceramic pedestal. [44] A chemical powder which corresponds to the desired gemstone is passed through this flames. This melts the ingredients which drop on to a plate and solidify into a crystal called a Boule. [44] For corundum the flame must be 2000°C. This process takes hours and yields a crystal with the same properties as its natural counterpart.Apart from jewelry, from earliest antiquity engraved gems and hardstone carvings, such as cups, were major luxury art forms. A gem expert is a gemologist, a gem maker is called a lapidarist or gemcutter; a diamond cutter is called a diamantaire. Find sources: "List of gemstones by species"– news · newspapers · books · scholar · JSTOR ( January 2019) ( Learn how and when to remove this template message) Musgravite was discovered in 1967 and is arguably the rarest gemstone in the world. It was first discovered in Musgrave Ranges, Australia, and later found in Madagascar and Greenland. The first sizable gem-quality specimen was discovered in 1993. As far as gem-quality stones, there are about ten specimens known and documented.