To share that which my be useful or interesting, but without enough experience to say that this IS a certain identification... Yours is possibly a mark of Curtis Jewelry Manufacturing (Providence, RI), who mark with initials "dce" and variations of which may include "de" with encircling "C" (your photo does appear as if the circle around "de" is not closed, or is it just worn?) Curtis Jewelry Manuf. are known for sterling and gold filled jewelry. Mark first used 1950.
Hi Theetonysonic, I have a bracelet with the same markings a conjoined lowercase de in a circle marked 3 times ( the de in the center is not in a circle ). I'm also looking for the maker but have had no luck so far. I researched the Curtis jewelry manufacturing that auaustin mentioned and the marks are definitely not the same although they are the closest if found so far. I'll attach images of my bracelet here so hopefully if anyone recognizes them they can let us know :) http://imgur.com/kqw0ohqhttp://imgur.com/kqw0ohqhttp://imgur.com/BVyNEGi