Solid 10K gold pendant with real large black diamond, Vintage Art Deco

Vintage Art Deco handmade pendant. Real solid 10 karat yellow gold and real (professionally tested) large black diamond stone. The stone is about 10 mm x 7 mm, and the pendant is 2.5 cm long (with bail). In excellent condition. Stamped 10 K and has a makers mark. Black diamonds are real natural diamonds that are heavily included with black carbon or hematite. This can make them slightly magnetic, but still much less magnetic than pure hematite. This one is slightly magnetic too, and only when I use a very strong rare earth magnet.