Modern fakes use "shell stone" (crushed shell mixed with resin). A gemological refractometer will show RI (Refractive Index) 1.52 for resin vs. 1.68 for calcite shell.
Modern fakes use "shell stone" (crushed shell mixed with resin). A gemological refractometer will show RI (Refractive Index) 1.52 for resin vs. 1.68 for calcite shell.