They are pretty rough looking, but I agree knowing if they are made from rock or metal would be a good start. The right item in the top pic might have a test cut on it.
"If you climb a good tree, you get a push."
-----Ghanaian proverb
"The danger we all now face is distinguishing between what is authentic and what is performed."
-----King Adz
-----Ghanaian proverb
"The danger we all now face is distinguishing between what is authentic and what is performed."
-----King Adz