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Black sand - Wikipedia, the free encyclopedia |
 | | Black sand is a heavy, weakly magnetic, glossy, semi-metallic 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. |
 | | 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 magma processes into a common mineral-suite that later becomes fl sands, after weathering and erosion. |
| en.wikipedia.org /wiki/Black_sand (169 words) |
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