Types of imitation pearls

Nowadays people also use imitation pearl which has a surface created by a scientific process, which are easily available and cheap. Today here will be a short instruction on the types of imitation pearls. It can de divided into three types, which can make you have a brief knowledge of imitation pearls.
1. Glass Beads：The beads are cover with as many as forty coats of pearl essence and hand polished between each coat. 
2. Plastic Beads：Make in the same process as that of glass beads, but is much lighter than glass beads.
These two types of beads of glass or plastic, are coated with a material known as guanine. The guanine is obtained from herring fish scales, where it occurs as tiny crystals embedded in tissues attached to the scales.
3. Mother-of-pearl shell beads：These are coated with the same substances as plastic and glass imitations. There are also some occasions that people sell uncoated mother-of-pearl shell beads, and claim those are pearls. White beads made from mother-of-pearl are one of the oldest types of imitation. The beads can be recognized with the naked eye due to their layered structure.
An older type of imitation pearl consisted of a hollow glass bead, the inside surface of which was coated with ‘essence d’orient’. The bead was then filled with wax.
Both of ‘conch pearls’ and ‘tridachna pearls’ can be easily be distinguished by its striped or banded structure, and absence of the ‘flame structure’. Under a 10x lens, the surface structure of imitation pearls has a smooth to somewhat granular appearance, which contrasts markedly with that of natural and cultured pearls.