Thulite, first found in 1820,  is the national stone of Norway, whose ancient name was Thule.  Here is a lovely little set, unused and in its oriiginal box. It consists of a small pendant and chain with matching ear studs. 

Condition: Excellent, unused

Marks:  925S on bale of pendant and butterfly backs

Size:  pendant 0.5" (1.25cm), ear studs 0.4" (1cm), chain 16.5" (42cm)

Year: 1980s?