[plas-er] 
| 1. | a surficial mineral deposit formed by the concentration of small particles of heavy minerals, as gold, rutile, or platinum, in gravel or small sands. |
| 2. | the site of a form of mining (placer mining) in which a placer deposit is washed to separate the gold or other valuable minerals. |
| placer mining n. The obtaining of minerals from placers by washing or dredging. placer miner n. |
| placer (plās'ər) Pronunciation Key
A surface deposit of minerals, such as gold or magnetite, laid down by a river. The minerals are usually concentrated in one area because they are relatively heavy and therefore settle out of the river's currents more quickly than lighter sediments such as silt and sand. ◇ The extraction of minerals from placers, as by panning, washing, or dredging, is called placer mining. |