Superior Swirl Slag, Sterling Silver Necklace

I recently purchased a few slabs of this very unique glass. It's call Superior Swirl Slag, and is found in Lake Superior in the upper peninsula of Michigan. This slag was made during the 1850's to 1870's and is traced to many of the furnaces that were once in operation near or along Lake Superior. It is technically a glassy slag left from a copper smelting mining process. As is typical of this glass, this cabochon shows a couple pinhead sized pits, which does not affect the aesthetics of the piece.

The pendant itself hangs almost 2" from the chain, and is 7/8" at the widest. (48mm x 21mm) The sterling silver chain is 17" long and finished with a sterling lobster clasp.

The sterling has a bright, satin finish.
(Item #:1345)