Jan 22 Antique Seth Thomas Shasta Style Adamantine Mantle Clock Running L-2 POSTED BY admin IN antique The “Adamantine” finish, which is a patented laminate finish from the late 1800’s, is in good shape for its age. This great looking clock was made by the Seth Thomas Clock Co. USA in the very early 1900’s, right around 1908. Tags : adamantine | antique | clock | mantle | running | seth | shasta | style | thomas