Abalone shells are often used for smudging ceremonies by the Native Americans in the United States and Canada.
These abalone shells have been cleaned and polished on the inside; the outside is clean, but still rough. The sizes have been obtained by measuring the longest side of the shell with a flat ruler. We weighed a random 5"-6" abalone shell as 4 oz., and a group of four 5"-6" as 1 lb.
When exported from the USA, Mexican abalone shells are subject to USFWS export processing fees at overseas rates, not at NAFTA rates as one would think.