Pearl identification

How do I identify pearls from say ciramic speres

Pearls have a luster to them that ceramic would not have.Also look around hole where they are strung,will have inner layers on pearl,the fake one will be smooth.Use loupe when looking at any gemstone.

Thanks techaa.
I have looked at what I know are pearls. By comparing them and using your sugestions i was able to identify three strands that are in fact pearls.