spall

 
Pronunciation: /spɔːl/

verb

[with object]
  • break (ore, rock, or stone) into smaller pieces, especially in preparation for sorting: the ore was spalled by young women seated at anvils
  • [no object] (of ore, rock, or stone) break off in fragments: cracks below the surface cause slabs of material to spall off

noun

  • a splinter or chip, especially of rock.

Origin:

late Middle English (as a noun): of unknown origin. The verb dates from the mid 18th century