Information: Wikipedia

A Stolperstein literally "stumbling stone", metaphorically a "stumbling block" is a sett-size, 10 by 10 centimetres (3.9 in × 3.9 in) concrete cube bearing a brass plate inscribed with the name and life dates of victims of Nazi extermination or persecution.

The Stolpersteine project, initiated by the German artist Gunter Demnig in 1992, aims to commemorate individuals at exactly the last place of residency—or, sometimes, work—which was freely chosen by the person before he or she fell victim to Nazi terror, euthanasia, eugenics, was deported to a concentration or extermination camp, or escaped persecution by emigration or suicide. As of 29 March 2018, over 67,000 Stolpersteine have been laid in 22 countries, making the Stolpersteine project the world's largest decentralized memorial.

The majority of Stolpersteine commemorate Jewish victims of the Holocaust. Others have been placed for Sinti and Romani people (then also called "gypsies"), homosexuals, the physically or mentally disabled, Jehovah's Witnesses, black people, members of the Communist Party, the Social Democratic Party, and the anti-Nazi Resistance, the Christian opposition (both Protestants and Catholics), and Freemasons, along with International Brigade soldiers in the Spanish Civil War, military deserters, conscientious objectors, escape helpers, capitulators, "habitual criminals", looters, and others charged with treason, military disobedience, or undermining the Nazi military, as well as Allied soldiers.

Cologne 18 January 1899 – Sobibor, 9 July 1943 - 44 years old - Merchant

Kreuznach, 17 May 1866 – Sobibor, 9 July 1943 - 77 years old

Keulen, 4 March 1894 – Sobibor, 7 May 1943 - 49 years old - Merchant

Hans Rudolf Goldschmidt was a jeweler. Rudolf's father Joseph was a jeweler / goldsmith and had a large and well-known jewelery shop at 1 Domkloster in Cologne. When Joseph died in 1928, Rudolf took over the company together with his brother Ernst and cousin Ernst Richard.

In March 1938 Rudolf came to Amsterdam with his mother Caroline Goldschmidt-Marcus. In 1942 they lived at Merwedeplein 38 III. They were arrested there during the raid on 20 June 1943.