Destructive Gemstone Tests: Acid Testing
Step 3: Practical Gemology
In some cases, a hot point test will not distinguish plastic simulants or imitations from natural gems. Some plastics release a protein smell when hot point tested, just like their natural counterparts. Natural coral, shell, and pearl release a protein smell. These organic gem materials are carbonates, just like malachite and rhodochrosite. You can make a positive identification of these gem specimens through acid testing, examining how they react to acid.