Not sure just guessing, it looks like petrified wood to me, again just guessing.
From my limited knowledge of geology and types of rocks, the stones probably have some iron in them due to its excessive reddish colour. Not certain but it might have as well some feldspar (I need to check this).Not sure just guessing, it looks like petrified wood to me, again just guessing.
Yes it does look like ohko stone. Thanks for hinting!Looks like ohko stone to me. If so yes its safe.