vintage carved stone mushroom, Mexican onyx travertine marble carving

Small figurine or fetish, a little stone mushroom about 2 1/4" x 2 1/4". This I think is Mexican onyx, probably 1960s or 70s vintage. There's an old price ($1.00) in grease pencil on the bottom. I love the pale ivory color, and they way the light shines through it like alabaster.