Ivory? gaming-piece on copper-alloy ring

Ivory (or a bone) gaming piece, probably turned because it has strong relief. Much damaged, original diam. c. 2.8cm. Back flat, front with markedly thickened and curving rim, indented centre with prominent boss, with little ridge around and bored hole clean through centre. Bored hole in rim stained around with copper oxide. Faussett illustrates this piece with a bronze suspension ring 1cm diam. - no knots. Obviously re-used as a pendant. Some iron stains also near suspension hole on front and back, and elsewhere on back. Found near neck.