While "delamination" would be a better description of this flaw, "lamination" is the accepted term.
Quote:Lamination Cracks
Definition: Lamination errors are planchet errors in which the surface of a coin cracks and flakes. It is generally believed that lamination errors are caused by contaminants in the alloy that cause the metal to separate along the horizontal plane. Lamination errors can develop before or after the strike. They are generally restricted to solid-alloy coins. The term "lamination error" is grammatically incorrect as the metal is actually delaminating. While "delamination error" would be the proper term, we're stuck with the terminology we've
inherited from previous researchers.