Got this off the bay, it was covered in oil and I cleaned it up a bit. It's natural. It appears to be a sedimentary stone of some kind. It's fine but not as fine as my coticules. It's old (the box had hand made brass hinges)
It's got some striations and is tan in color.
Any help would be appreciated, I have never seen anything like it.
It's got some striations and is tan in color.
Any help would be appreciated, I have never seen anything like it.