Numerous sites are known globally on continental shelves where placer deposits, primarily of metallic heavy minerals, have been mechanically concentrated by flowing water as a consequence of their higher density (> 3.2 g cm − 3) relative to the bulk of detrital minerals consisting mostly of quartz and feldspar (2.5–2.7 g cm − 3).The resistance of a mineral (hardness, cleavage, density ...
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