Gamma irradiation turns the nacre of freshwater pearls very dark, and often also imbues a metallic lustre with rainbow orient. Strangely, it has no effect on salt water nacre but will turn the nucleus dark which shows through the layer of nacre, making the pearl look grey or blueish There is no danger of radiation contamination from irradiated pearls.
or popcorn pearls have a knobbly surface which resembles..popcorn. This granulation is often mixed with patches of high lustre surface. When the Chinese freshwater pearl business was starting up most of the pearls were, at least to some degree, popcornish and oval in shape. Term also used for the earliest Chinese freshwater pearls which were called Rice Krispie pearls.
Loose, undrilled white rosebud /granulated pearls
Gold Leaf Pearls
This is the name we give to the extremely beautiful lustrous gold pearls which are natural pearls with a layer of aragonite with an incredible lustre – so it does indeed look as if a layer of gold leaf has been applied to the pearls.
These pearls show the stunning gold colour which
looks as if gold leaf had been applied to the pearl surface
A large oyster (variety of Pinctada maxima) used in some countries to produce South Sea cultured pearls; it produces a yellowi nacre, and pearls that typically range from off-white to rich, deep gold in colour.
Loose undrilled gold south sea pearls waiting to be paired for earrings
An optical phenomenon which causes the hue of the pearl to change colours depending upon the angle from which the pearl is viewe. Popularly called colour-change pearls