Bakelite and its chemical sister Catalin are early plastics that have gained much popularity in recent years. They have no seams and are heavier than many other plastics.
One easy test for Bakelite uses the product Scrubbing Bubbles, Simichrome, or original 409 spray cleaner. Spray a small amount on a paper towel or Q tip and rub a small area of the plastic item you wish to test. If the paper towel or Q tip turns yellow, there is a good possibility that the item may be Bakelite. Most other plastics will not change the color of the paper towel.
Another test for bakelite is to hold the item under hot water. There is a very strong chemical odor if the item is bakelite, catalin, or celluloid. There is little odor with more modern plastics.
Celluloid is one of the early plastics. It often has a very nice shine and can have seams. If you leave celluloid in a plastic bag for a while, you should smell a vinegary smell when the bag is opened. Celluloid can deteriorate over time and once this deterioration begins it is almost impossible to reverse or stop.
Casein plastic or Galalith is a light-weight, early milk-based plastic. It often has a coating of a bright or dark color over a white base. Into the beads are carved various designs that show the white underlining. Casein plastic cannot be molded and does not have mold lines. It is cut and then polished by tumbling. Never put casein plastics in water to soak because it will ruin the beads.
Lucite is a brand name of acrylic plastic that was invented and produced by DuPont Corporation. It is very durable, keeps a glossy finish over time, and often has a distinctive "moonglow" somewhat similar to cats-eye optic glass beads. Lucite is a thermoplastic that was used extensively in jewelry during the 1950's and 1960's.
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Because elephants are endangered species worldwide, new importation of elephant ivory pieces is banned, though vintage ivory can be sold within the US. Elephant ivory and bone are both relatively light in weight compared to glass or stone. Ivory has a definite grain that often swirls like wood with cross-hatching of more dense-appearing color. Bone may have striations but these are generally straight, with a rather even color, not saturated into distinct bands.
As it ages ivory turns yellowish rather evenly. Aging bone shows dark brown specks that are usually visible under a magnifying glass. Ivory pieces often show more delicate and intricate carving, though both ivory and bone carvings should be treasured for the artistry of the hand work that went into making them.