It was impressed GI and 830 within a circle of dots - a mark used c.1919-27.
Offered together with a pair of similarly marked ear pendants, each designed as a blossom set with labradorite cabochons, the lot went well above its estimate of $2000-3000.
Skinner specialist Victoria Bratberg said: "The early pieces we have sold featuring labradorite [a favourite stone of Jensen's found in both Scandinavia and Canada] usually bring very strong prices at auction. A similar necklace is pictured in Georg Jensen: A Tradition of Splendid Silver by Janet Drucker."
The sale on September 9 also included 33 lots from the family of the Cotswolds-trained American Arts and Crafts jeweller and enameller Frank Gardner Hale (1876-1945).
The buyer's premium was 23%.