Cosman Troostwijk and his wife had four children. One of the daughters was Hendrina Julia Troostwijk. She was married to Albertus Julius (also known as Albert Jules) van Gelder.
Cosman Troostwijk stored a case with silverware and jewellery with depositors in Leeuwarden. The case was located by the Nazi authorities and seized.
The archive of the Stichting Sieraden-Comité contains among other th…