Obsidian bearing well-developed conchoidal (clam-shell-shaped) fracture with concentric ribs, as displayed at the recent U.S. Science and Engineering Festival on the National Mall by a local gem/fossil/mineral club.
Obsidian bearing well-developed conchoidal (clam-shell-shaped) fracture with concentric ribs, as displayed at the recent U.S. Science and Engineering Festival on the National Mall by a local gem/fossil/mineral club.
i am learning about conchoidal fractures now. The are beautiful. I wish I could find an explanation for them that is made for beginners and easy to understand.
Thanks for the great photo!
p.s. I am glad your fingernails were clean!lol
You strike the lithic with an object, preferably another rock.