What marks are on it?

A small bird's wing was used to indicate the use of the material bois durci.

An infinity sign is the logo of Bakelite and thus frequently indicates the material phenol formaldehyde but the company made many other plastic materials. It only appears on Bakelite promotional mouldings. Bakelite did not make mouldings for the general market.

Recycling triangles were introduced in 1988 so any object with these on must date from that year or later.

Smooth circular marks are a sign of the use of ejector pins to push the moulding from the mould and thus of injection moulding.

An imperfection on an otherwise smooth surface may be a residue left at the spot the material has been forced into the mould and thus indicate the use of injection moulding. Such marks can be extremely hard to detect and they may not be where you might expect to find them, for example centrally placed on the base or on the edge. They can be polished off so their absence does not tell you anything.

The following are trade names that frequently appear on mouldings. They are associated with the materials indicated: