Bowlerite Cabochon - approx. 12 x 8 x 3.6 mm

Bowlerite Cabochon - approx. 12 x 8 x 3.6 mm

Repurposed outer resin layer of a vintage bowling ball, unbacked, but may have part of the bowling ball core on the back and sides, see photos for details

Coin for size reference: approx. 20mm diameter (about 1mm smaller than a UK 20p or U.S. nickel)