Occurs in pegmatites and high-temperature quartz veins also in cavities in granites and rhyolites. A maximum of 30 % of the F site is occupied by OH in natural topaz although in some very rare cases OH-dominant members have been described in high-pressure rocks see Unnamed OH-analogue of Topaz Zhang et al. 2002 .
Mountaintop removal mining is a form of surface mining in which explosives are used to blow the tops off some Appalachian mountains. This particular type of mining is used mostly in the Appalachian coal fields of West Virginia Kentucky Virginia and Tennessee in the United States. Once the topaz has been mined it is polished.
Topaz is mined in Australia Namibia Nigeria Russia Pakistan Brazil California New Hampshire and Utah. The gem is mined in what is called surface mining. It is also mined in underground mines. There are five different types of surface mining. Strip mining open pit mining dredging highwall mining and mountaintop removal mining.
Many salt mines use the "room and pillar" system of mining. Shafts are sunk down to the floor of the mine and rooms are carefully constructed by drilling cutting and blasting between the shafts creating a checkerboard pattern. After the salt is removed and crushed a conveyor belt hauls it to the surface.
Imperial Topaz History. Imperial Topaz has long been known as precious Topaz. It is highly sought after. Its color is like the setting sun and it was given its name by 17th century Russian Tsars. This is because Russian Tsars claimed the exclusive rights to the pinkish Topaz gems that were mined throughout Russian.
The mining techniques adopted to extract gemstones invariably reflect the nature of the deposit: primary deposits in hard rocks worked underground or in open pits and secondary deposits found in sedimentary soft-rock placers . The mineralogy of a gem dictates the type of geological environment in which it can be found.
A new find of good Topaz crystals is the Zapot Mine near Hawethorne Mineral Co. Nevada which produces rare green crystals. Topaz is found in the gem pegmatites of San Diegeo County in localities such as the Little Three Mine in Ramona and the Ware Mine in Oak Grove. Colorless Topaz come from the Pikes Peak area in El Paso Co. Colorado ...
The lifecycle of a gold mine. People in hard hats working underground is what often comes to mind when thinking about how gold is mined. Yet mining the ore is just one stage in a long and complex gold mining process. Long before any gold can be extracted significant exploration and development needs to take place both to determine as ...