This is a historic regional term from the Cornish tin mining industry for ore that has passed through a stamp mill. The stamping process crushes the raw mined rock into a fine sand or slime, liberating the heavy tin mineral from the lighter quartz and granite waste. It represents the intermediate stage before final washing and concentration.
Heard on the job
We need to run another batch of witts over the sleeping table to get the grade up.
Related terms
Black tin
Dressed and washed cassiterite ore that is ready for the smelting furnace.
Sleeping table
A stationary, inclined wooden platform historically used to wash and concentrate crushed ore.
Tossing
A traditional mineral processing technique that separates heavy ore from lighter waste by violent agitation in water.