Invented in 1907, Bakelite plastic was used to make a variety of objects such as kitchenware, telephones and radios. Bakelite buttons are collectible items not only because of their age, but because they often have unique patterns embossed in them. The buttons were popular in the 1930s and worn more for decoration than function. If you have a stash of buttons, sift through them to find potential Bakelite buttons then try a few tests to identify true Bakelite buttons.
Sift through your buttons to find possible Bakelite buttons. Any buttons made of wood or metal are not Bakelite. Plastic buttons with unique patterns (such as flower designs) should be pulled out as potential Bakelites. Buttons in the shape of a flower or with a marbleized center are also candidates.
Rub a button between your fingers or clasp it until it feels warm. You can also drop several buttons in a cup of hot (hand hot, not boiling) water to warm them. Once warm, smell the button. Bakelite was made with a formaldehyde resin and will give off a formaldehyde smell when warm. Formaldehyde is used in science classes to preserve specimens, so try to remember what your high school biology class smelled like.
Dampen one end of a cotton swab with the liquid household cleaner. Touch the damp swab to the back of the button (be sure it is touching a plastic part if the button has other decorations on it). Look at the end of the swab. If it turned yellow, the button is made of Bakelite. If not, the button is another type of plastic.
Tap two buttons together that you think are Bakelite. Unlike other plastics that make a "tink" sound, the Bakelite pieces will make a "clunk" sound.