Imitation pearls are artificial manufactured "pearls." They have no real value as a gemstone. Imitation pearls can be made from glass, ceramic, shell or even plastic.
The bead is then coated with varnish and/or other materials in order to produce a pearl-like lustre and iridescence.
Generally they are sold under descriptive terms such as "faux," "simulated," "artificial," or "man-made." Sometimes regional names are also used: "Mallorca pearls," "Red Sea pearls," "Laguna pearls," etc.
It is considered a deceptive trade practice to offer imitation pearls without clearly identifying them as such. A common test to determine whether a pearl is genuine or imitation consists of scraping the pearl gently across one's teeth.
Imitation pearls feel smooth to the tooth, while genuine cultured pearls feel slightly gritty or abrasive due to the crystalline structure of the nacre.