Black sand

Black sand

Black sand is a heavy, glossy, partly magnetic mixture of usually fine sands, found as part of a placer deposit.

Black sands are used by miners and prospectors to indicate the presence of a placer formation. Placer mining activities produce a concentrate that is composed mostly of black sand. Black sand concentrates often contain additional valuables, other than precious metals: rare earth elements, thorium, titanium, tungsten, zirconium and others are often fractionated during igneous processes into a common mineral-suite that becomes black sands after weathering and erosion.

Several gemstones, such as garnet, topaz, ruby, sapphire, and diamond are found in placers and in the course of placer mining, and sands of these gems are found in black sands and concentrates. Purple or ruby-colored garnet sand often forms a showy surface dressing on ocean beach placers.

ee also

* Diamond
* Mining
* Placer deposit
* Heavy mineral sands ore deposits
* Punaluu Black Sand Beach

External links

* [http://geology.wr.usgs.gov/parks/coast/sand/blacksand.html The Geology of Black Sand]
* [http://www.egsma.gov.eg/black_sands.htm Black Sands of the Nile River]
* [http://www.viequestravelguide.com/black-sand-beach-vieques-puerto-rico-06.html Black Sand in Vieques, Puerto Rico]
* [http://www.alaskafreegold.com Alaska Mineral and Mining Images]


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