corundum, ruby, sapphire, Thailand.12, gems

Credner presents a broad geographical account of Siam based on his extensive travels and field investigations, combining physical geography, geology, climate, vegetation, settlement, population, agriculture, communications, and economic development. He describes the major geographical regions of the country and relates their landscapes and patterns of human occupation to underlying geology and relief. Mineral resources and mining form part of the economic-geographical treatment, including Siam’s important tin industry and other mineral occurrences, while the gem-producing districts are considered within the wider discussion of natural resources. The work is particularly valuable as a detailed picture of Thailand in the early 1930s, shortly after the political changes of 1932, and contains numerous photographs, maps, and observations derived from Credner’s own fieldwork. For gemological purposes its importance lies chiefly in the geographical and geological context it provides for Siam’s mineral and gemstone resources rather than in detailed mineralogical descriptions.