What scale material? Purple and brown dust

I got a couple new razors the other day and I was messing a little with them today. I popped a few out of the scales and removed some rust, then worked the scales a little with some fine sandpaper. I can tell two of them are not celluloid, so I was wondering what they're made of. They are both opaque black in color, and definately some plastic variety.

One smells kinda like burnt plastic, it seems dense, heavy and inflexible, and it dusts brown. I'm guessing this would be bakelite?

The other is very different. It feels a lot softer, very flexible, and sands purple. There is a chemical/artificial smell but I could not place it. Anyone got any input as to this material?

brown dust and burnt smell sounds like hard rubber to me
Aint got a clue on the other one

Wait you said opaque, that mean light shines trough?
dont think its rubber then

The brown dust one is almost certainly Vulcanite. (hard rubber)

My guess for the other is bakelite or celluloid. Many of the "newer" celluloids were very flexible.

opaque means no light passes through, it is a very solid color. Translucent means light shine through :)

The one giving off a pinkish dust could be Ebonite (similar to vulcanite, a hardened rubber). It used (among other sulphides) mercury as a hardening agent (mercuric sulphide - both ebonite and vulcanite depend on sulphur compounds to harden them). Both have a rubbery/sulphur smell.

Bakelite often gives a brownish dust - it used wood-flour as the filler and often smells of formaldehyde. It is probably heavier than most other synthetics. sometimes asbestos was used as the filler.

The brown dust isn't really indicative of one or the other - the black often goes to brown as a result of oxidation. The smell is the real test. Rub your finger or thumb very briskly on bakelite and smell it asap to try and get the formaldehyde smell (formaldehyde is used as a specimen preservative in labs).

Regards,
Neil