17” Tri-Strand Red Coral Graduated Bead Necklace 46g

Found more coral jewelry at the same thrift shop I found the coral bar pins. This necklace has three strands of red coral beads that graduate in size from the smallest being 4mm to the larger 9mm beads. The clasp is gold washed sterling, with another marking I cannot decipher. The coral is undyed/natural colored (I dropped a small drop of acid on a bead, it fizzed and didn’t remove any color).

I’m asking for assistance on identifying this particular coral and maker of the piece. It’s a red color, but not deep red color. I’m not sure if the coral is Japanese, Mediterranean, etc.

This piece weighs 46.8g total, and measures 17 1/2” long.