Not hallmarked or stamped but tested as 10k, it does have an illegible makers mark to the rear. Weighs approx 3.5 grams without the round screw down lug & measures 19mm in diameter. Nice condition & just needs a light clean. Does not come with a box. No history is known about the item.
PRICED TO SELL !!! Weighs approx 2.2 grams excluding the screw on back & measures 13.5mm wide x 15mm high. Stamped 10k to the rear, Diamond tested with a Diamond tester. Very nice...