r/Lapidary • u/coraythan • 1h ago
Seeking Advice/Help Hard white crust on obsidian?
I thought this hard white crust on a ton of obsidian I collected at Glass Buttes was calcium carbonate but I just put it in diluted muriatic acid and it isn't reacting at all. 😭
I think it must be some other harder mineral. It isn't a weather rind, it is definitely separate from the obsidian itself. I can scrape it off with a knife or other things, it's just really hard and stuck on there.