Arrasta: This was an early method of crushing and recovering gold.
The ore was placed in the hole and mercury added. The rock next to it with the holes in would have been used to grind the ore, power being supplied by a water wheel. The mercury would have absorbed the gold into itself and at the end of the process the amalgam would have been recovered and the gold extracted.  (Clogau-Gold-Mine-2-User-Album-Image-007)

Arrasta

This was an early method of crushing and recovering gold. The ore was placed in the hole and mercury added. The rock next to it with the holes in would have been used to grind the ore, power being supplied by a water wheel. The mercury would have absorbed the gold into itself and at the end of the process the amalgam would have been recovered and the gold extracted.