New vintage stone heart pendant

New vintage stone heart pendant Quick list. Measurements to follow. Genuine stone. Yellow-orange-beige warm colours. Polished heart shape with natural striping. New vintage c. 1970s. Genuine stone (just not white jade). Goldtone metal. Probably made in Korea. Hallmark on bail: ???? But most of the hallmarks from this company say “NICCOP”? or “NICSOP”? or “SILVER”. Group photo shows variety in the collection. Chain not included.