This appears to be a vintage mother-of-pearl disc or coin shell necklace, likely from mid-century Japan, featuring iridescent round shell links connected with metal hardware.

Clasp Mechanism & Style

• The Tongue: The rectangular metal tongue piece (on the right) slides directly into the decorative housing mechanism.

• The Housing: The round gold-tone decorative receiver features a beautifully embossed sunburst or floral wheel pattern with radial fluting.

• The resale value of a vintage mid-century Japanese mother-of-pearl disc necklace generally falls between $15 and $50 on secondary marketplaces.