Shell pearls also exhibit perfect uniformity in shape, color and reflectivity. These synthetic pearls are typically created in South Sea pearl sizes - 10.0-14.0mm ranges are the norm - and pastel colors traditionally seen in luxury pearl types: white, black, grey, gold, pistachio, brown/chocolate, and soft pinks - the better to fake you out, my dears.
Shell pearls can be made in two ways:
- The first and most common method is by crushing the interior mother-of-pearl found in mollusk shells into a fine pearlescent powder. This mother-of-pearl powder is used to coat a bead nucleus, very similar to the process used in creating Majorica pearls.
- The second method creates rounded beads out of a saltwater pearl oyster's shell using the thickest part near the hinge. These pieces are smoothed and rounded out into perfect spheres and then dyeing them in various colors. The shell pearls are then baked at high temperatures to ensure the coloring is permanent and then given a high polish.
The Tooth Test won't be effective with Shell Pearls due to their composition (ground up mother of pearl or solid shell), and these pearls can also exhibit surface irregularities, making the evaluation even tougher.
Focusing on the "luster" and colors will be most helpful in determining whether the pearls you're looking at are genuine or Shell Pearls.
Shell Pearls will display very uniform rates of light reflection, and their colors will all be solid, uniform hues with little to no natural shading/variation.