Adamantine Finish Black Mantel Clock (Black Marble Style)
Seth Thomas · Collectibles & Antiques > Vintage Clocks
Era / Decade
Late 19th Century (Circa 1880-1895)
Material
Wood case with 'Adamantine' celluloid veneer (designed to mimic marble), metal movement, brass-rimmed glass bezel, and faux-finished (marbled) pillars.
Condition
Good/Fair. The clock shows significant wear to the black finish with visible chips on the base edge. The dial is heavily aged/patinated, and there is evidence of dust accumulation. Mechanical functionality is unknown.
Demand Level
Moderate. Antique clocks have a dedicated niche following, though unrestored pieces with cosmetic damage take longer to sell.
Resale Value
Estimated Resale Value
$75 - $150 (working condition) / $40 - $60 (parts/as-is condition)
Estimated Retail Value
$15.00 - $25.00 (original 1880s price) / Comparable modern high-end mechanical mantel clocks: $400 - $600.
Comparable Sales
Similar Seth Thomas Adamantine clocks in working order sell for $125-$200 on eBay. Non-working models with cosmetic wear typically sell in the $45-$70 range.
Description
Antique Seth Thomas mantel clock featuring the iconic Adamantine finish. Originally patented in 1880, this clock mimics the look of heavy marble or onyx with more durable wood and celluloid. It features a Roman numeral dial, dual winding points, and classic architectural pillars with decorative botanical scrollwork engravings on the black facade. A quintessential piece of Victorian-era Americana decor.
Key Features
Authentic Seth Thomas movement, highly collectible Adamantine finish, classic Victorian architectural styling, dual chime/time movement.
Authenticity Indicators
Distinctive 'F-S' (Fast-Slow) adjustment slot above the 12 o'clock mark; Adamantine labeling often found on the back or bottom; specific pillar and scrollwork design typical of Seth Thomas late 19th-century catalogs. High confidence.
Flaws to Note
Visible chipping and paint loss on the lower base; heavy yellowing and spotting on the paper/metal dial; mechanical status is untested (requires a winding key); surface grime throughout.
Selling Guide
Where to Sell
eBay (best for reaching clock collectors), Etsy (if marketed as 'Antique Decor'), or a local Antique Mall booth.
Selling Tips
Always specify if the pendulem and key are included. Do not attempt to over-clean the dial as it can strip the numbers. Use keywords like 'Victorian', 'Adamantine', 'Seth Thomas', and 'Steam Punk' to attract different buyer types. If it doesn't run, list it as 'For Parts or Repair' to avoid returns.