I found this on a beach near Otter Ferry, Scotland. I'm inexperienced at identification so I was hoping someone else knew the answer. To me it looks like quartz with some sort of iron/hematite in the middle, but what do I know? 
I'm particularly interested in what the brown wavy stuff is. I'd love to cut it open to have a look inside but I don't have any tools to do so.
I'm particularly interested in what the brown wavy stuff is. I'd love to cut it open to have a look inside but I don't have any tools to do so.
