An artificial man-made imitation (produced by several methods) of a natural pearl or of a cultured pearl. Such imitations were first made in France before the 15th century in the form of a hollowglass bead dipped into acid to produce an iridescent surface and filled with wax to provide solidity and weight; they were used profusely as scattered trimmings on dresses and hats. In the 17thcentury an improved version was produced in France by first coating the interior of hollow glass beads with essence d'orient to provide a nacreous appearance; they were called 'Roman pearls'.In the 19th century a further improvement was developed in France by spraying the exterior of solid glass beads (having a string hole) with essence d'orient, sometimes applying up to ten coats; theywere called 'Venetian pearls'. Such imitation pearls are identifiable by an unridged surface, by a smooth feeling when passed over the teeth, by showing a mark when pressed by a pin-point, orby being readily scratchable, as well as by X-ray and by testing for specific gravity (usually higher than 3,0). There are many trade-names for imitation pearls.