From a website on testing bakelite:

Rub your fingers over the piece, until it is warm, then smell. It is unforgettable - formaldehyde or a carbolic acid. Familiarize yourself with this odor. Not all pieces will have the same odor intensity, but it will be there.

Immerse the piece in hot water (not with rhinestones, please).The smell should be the same.

Bakelite has a clunky sound. Hit two plastic pieces together, then two bakelite - check the difference. Feel the difference.

Hot needle - be careful though. Heat a needle until it is red hot and then pick an inconspicuous place on the piece to stick the needle in. Wait just a second - not too long! There's that smell again! Also, non thermoplastics will melt and celluloid is extremely flammable so again BE CAREFUL!

There is a product on the market called "Scrubbing Bubbles" bathroom cleaner. When put on a q-tip and touched to bakelite, the q-tip will turn yellow. I have only tested this product and have had successful results. No harm has come to the bakelite.