Question

What is blister copper?

Answer 1

Answer:

Hi,

BLISTER COPPER is a

partly purified copper with a blistered surface formed during smelting.

MARK AS BRIANLIST IF POSSIBLE

Answer 2

The slightly impure copper had impurities, mostly sulphur dioxide which bubbled up through the copper as it solidified. That gave a blistered surface and the results of the smelting were called blistered copper.