corundum, ruby, sapphire, Kenya.12, Tanzania.12, East Africa, geology.11, gems

An illustrated survey of East African gemstones, emphasizing the deposits of Kenya and Tanzania and combining regional geology with accounts of discovery, exploration, mining, and gemological properties. Following an introduction to the geological setting, Keller discusses diamonds, ruby and sapphire, emerald and alexandrite, tanzanite, garnets, tourmaline, and green opal, with a concluding chapter on less prominent gem materials. Individual accounts place the deposits within their geological environments while recording their development and the people involved. Particular subjects include tanzanite from Merelani and prase opal from Haneti Hill, Tanzania. Photographs of rough and cut stones, inclusions, mining operations, and historical scenes complement locality maps, including some previously unpublished examples. Contributors include E.J. Gübelin, Harold and Erica Van Pelt, and J.I. Koivula. Appendices list 177 noteworthy gem localities with geographical coordinates and document East African gemstones in the collections of the Los Angeles County Natural History Museum and the Smithsonian Institution. References accompanying each chapter provide access to the region’s geological and gemological literature. The volume offers a substantial record of East African gem deposits and industry as understood at the beginning of the 1990s.