The most used shells in cameo makign are:
1. CASSIS MADAGASCARENSIS: also colled “Sardonix helmet”, about 30cm tall. I’ts colour is dark brown on the bottom, and white on the surface, where the shell is engraved;

2. CASSIS RUFA: also called “Cornelian Helmet”, about 16cm tall. This shell has an inner reddish layer, and on the outside, where the shell is engraved, it’s flash-coloured;