An Art Deco platinum, diamond and onyx pendant watch, by Dreicer & Co.

An Art Deco platinum, diamond and onyx pendant watch, by Dreicer & Co.
The triangular silvered dial with Roman numerals, and engraved edge, the case back set with a domed black onyx within a single-cut diamond border, centrally-set with a triangular cut-cornered diamond, circa 1930, case 29mm wide
Dial signed Dreicer & Co