Nov 08 Antique Seth Thomas Adamantine Mantle Clock 1901 Nice POSTED BY admin IN antique Adamantine is a celluloid veneer, glued to the wood case. Adamantine veneer was made in black and white, and in colored patterns such as wood grain, onyx and marble. The 1880 is the patent date for the adamantine finish. Tags : adamantine | antique | clock | mantle | nice | seth | thomas