Three view of the same silver locket, front, opened and reverse.
The photo in the opened view of the locket is of Ida Colldén.
Text on reverse of locket reads
Minne af 30de födelse dag 20/11/1894
Translated this is
Memory of 30th birthday 20/11/1894
The locket, one would guess, was a gift to Johan Bernhard Colldén on on his 30th birthday from is wife Ida.