Philately · Erts 1951
Tin Mining on Postage Stamps
In her illustrated essay, M. J. Baronesse van Heerdt-Kolff surveys mining on postage stamps around the world. The section on tin specifically names Bangka and Billiton, discussing deposits on land and in submerged ancient river valleys.
The author remarks that, as of 1951, Indonesian stamps had not directly depicted tin mining. She connects two stamps from Kenya–Uganda–Tanganyika with East African scenery and with tin prospecting by engineers associated with Billiton Maatschappij in the Kagera region between 1929 and 1932. These are not stamps issued for Belitung or showing a Belitung mine.
Historical source: M. J. Baronesse van Heerdt-Kolff, “Mijnbouw op postzegels”, Erts — Maandblad der Billiton Bedrijven, 1951, pp. 133–137. These are period descriptions, not a current scientific inventory. Illustrations reproduced from the supplied historical scans; check rights before public publication.