Gold Swiss amethyst and diamond set cylinder Circa 1820

Gold amethyst and diamond set watch
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A yellow gold Swiss amethyst and diamond set open faced watch, circa 1820, gilt movement with cylinder escapement, gold cuvette with purple transculescent enamel insets.
White enamel dial, Roman numerals.
Case back set with oval amethysts and circular-cut diamonds.
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Diameter: 35 mm
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Signed: No Name