xoB sent this along, and I did see it somewhere else earlier, can't remember where.
Folk artists have used just about every material on earth. That includes earth and dirt, as last week linkers were interested to see perfectly round, highly polished balls of dirt as folk art from Japan.
When the US first minted the buffalo nickel in 1913, the practice of carving a new face onto the nickel was started, because the coin was thick and its metal was malleable.
Nickels were carved by several practically unknown artists - including actual hobos - and those early works are now collectable. But modern nickel-scratchers keep up the practice and create new works, and most in the set above are modern.
Wikipedia entry