The symbol :/.

The other day I dreamed I was window shopping with the stroller in tow. I was weaving in and out of shops. One shop I stopped in was a jewelry shop. I was looking pretty hard for a window shopper. When this man who worked there came out. He wasn’t dressed as nicely as someone who worked at a place like that should. He had long brown hair tied back. And he was wearing jeans and a t-shirt. Right before I left he came behind me and handed me a black stone it had the symbol :/. On it he said “take this for spirituality”
And now I’m on a quest to figure out what language or ancient sign this stone had on it. I think it has a meaning to it. I would like to understand.
Is it Japanese?