Placer deposits or bulk excavated earth that holds sufficient gold, gems, or ore to justify the costs of washing and extraction. The term originated in placer mining to distinguish profitable gravels from barren overburden. If the concentration of the target mineral drops below the breakeven cost of processing, the material is reclassified as waste rock or dirt.
Heard on the job
We finally hit pay dirt at the bottom of the trench, so get the wash plant running.
Also heard as
- pay gravel