lot large abalone shells, natural unpolished seashells for crafts or beach decor

Lot of four large abalone shells with rough, unpolished texture inside and out.

The largest shell measures about 8 1/2" x 7 1/4" 3 1/23". The smallest measures about 7" x 5 1/2" x 1 1/2".

These are more than 30 years old, out of an estate. I'm not sure of the type of abalone, or where these came from originally.