Search results
Results from the WOW.Com Content Network
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 ...
Elbaite is allochromatic, meaning trace amounts of impurities can tint crystals, and it can be strongly pleochroic. Every color of the rainbow may be represented by elbaite, some exhibiting multicolor zonation. Microscopic acicular inclusions in some elbaite crystals show the cat's eye effect in polished cabochons.
Tourmaline was sometimes called the "Ceylonese Magnet" because it could attract and then repel hot ashes due to its pyroelectric properties. [ 5 ] Tourmalines were used by chemists in the 19th century to polarize light by shining rays onto a cut and polished surface of the gem.
Calcite. Manganoan calcite (var.); Caledonite; Canasite; Cancrinite. Vishnevite; Carletonite; Carnallite; Cassiterite; Catapleiite; Cavansite; Celestite; Ceruleite ...
Tourmaline is part of WikiProject Rocks and minerals, an attempt at creating a standardized, informative, comprehensive and easy-to-use rocks and minerals resource. If you would like to participate, you can choose to edit this article, or visit the project page for more information.
Large (up to 1.8 cm) yellow londonite crystals associated with rubellite tourmaline. Londonite is an unusual caesium-rich heptaborate. [1] The Borate Minerals are minerals which contain a borate anion group. The borate (BO 3) units may be polymerised similar to the SiO 4 unit of the silicate mineral class.
"Imperial Porphyry" from the Red Sea Mountains of Egypt A waterworn cobble of porphyry Rhyolite porphyry from Colorado; scale bar in lower left is 1 cm (0.39 in). Porphyry (/ ˈ p ɔːr f ə r i / POR-fə-ree) is any of various granites or igneous rocks with coarse-grained crystals such as feldspar or quartz dispersed in a fine-grained silicate-rich, generally aphanitic matrix or groundmass.
Greisen is a highly altered granitic rock or pegmatite, usually composed predominantly of quartz and micas (mostly muscovite). Greisen is formed by self-generated alteration of a granite and is a class of moderate- to high-temperature magmatic-hydrothermal alteration related to the late-stage release of volatiles dissolved in a magma during the ...