Placer Deposits.Like gold, rare earths are relatively heavy and...

Placer Deposits.

Like gold, rare earths are relatively heavy and can beconcentrated in gravels by the action of water in streams and beaches. Placerdeposits can either develop as a result of in-situ weathering, or be a result of weathering combined with water action to create alluvial deposits. Monazite and xenotime are the two minerals most commonly concentrated. Palaeoplacers are simply ancient placer sands which have been buried by subsequent deposits.

Examples of placer deposits of rare earth elements includetin-rich river placers in Malaysia, and palaeoplacers in Witwatersrand, South Africa, and Elliot Lake, Ontario.