Jacob de Jong was a member of the Diamond Workers Union and apprenticed under I.J. Asscher. He began his apprenticeship in 1929 and likely was working as a diamond worker in some capacity prior to the occupation.
Addition
Jacob de Jong was a member of the Diamond Workers Union and apprenticed under I.J. Asscher. He began his apprenticeship in 1929 and likely was working as a diamond worker in some capacity prior to the occupation.