Search results
Results from the WOW.Com Content Network
Gem and specimen tourmaline is mined chiefly in Brazil and many parts of Africa, including Tanzania, Nigeria, Kenya, Madagascar, Mozambique, Malawi, and Namibia. It is also mined in Asia, notably in Pakistan, Afghanistan, and Indonesia as well as in Sri Lanka and India, [25] where some placer material suitable for gem use is found.
Rubellite is the red or pink variety of tourmaline and is a member of elbaite. Rubellite is also the rarest gem in its family. [2] It is occasionally mistaken for ruby. [3] These gems typically contain inclusions. [4] Notable countries where rubellite can be mined include Afghanistan, Brazil, Madagascar, Myanmar, Nigeria, Russia, and the United ...
In 1979, Gemstones Corporation of Pakistan was established to develop the gemstones sector in Pakistan, however in 1997 the corporation liquidated. [3] Now a number of organizations are working in this sector including All Pakistan Commercial Exporters Association of Rough & Unpolished Precious and Semi Precious Stones (APCEA) and Pakistan Gems and Jewellery Development Company (PGJDC).
Examples include aquamarine, tourmaline, topaz, fluorite, apatite, and corundum, often along with tin, rare earth, and tungsten minerals, among others. [17] [3] Pegmatites have been mined for both quartz and feldspar. [26] For quartz mining, pegmatites with central quartz masses have been of particular interest. [26]
The mineralogy of the gem deposits varies widely with, among others, corundum (sapphire, ruby), chrysoberyl, beryl, spinel, topaz, zircon, tourmaline, garnet being common. [2] Residual deposits are mainly found in flood plains of rivers and streams. The metamorphic types of gems constitute 90% of the gem deposits in Sri Lanka.
Topaz on matrix from Dassu in Gilgit Baltistan Brookite and Quartz mineral from Balochistan. Gemstones, also known as semi-precious stones or gems, are minerals widely used in jewelry and for ornamental purposes.
Elbaite, a sodium, lithium, aluminium boro-silicate, with the chemical composition Na(Li 1.5 Al 1.5)Al 6 Si 6 O 18 (BO 3) 3 (OH) 4, [4] is a mineral species belonging to the six-member ring cyclosilicate tourmaline group. Elbaite forms three series, with dravite, with fluor-liddicoatite, and with schorl.
The world's largest and most valuable gem opal "Olympic Australis" was found in August 1956 at the "Eight Mile" opal field in Coober Pedy. It weighs 17,000 carats (3.4 kg; 7.5 lb) and is 11 inches (280 mm) long, with a height of 4 + 3 ⁄ 4 in (120 mm) and a width of 4 + 1 ⁄ 2 in (110 mm).