Pitted onyxApproved: beseder.pass

Jewelry Discussion
1

Looked up onyx composition. True onyx is calcite (calcium
carbonate) so would slowly dissolve in perspiration if the skin
was at all acidic. FWIW Geo.

http://varioned.com/josmar/compo.html
http://www.ugs.state.ut.us/bandcalc.htm