"The Bureau of Mines investigated the Ketchem Dome Tin Prospect in east-central Alaska to evaluate the tin resource. The studies included field investigations, mineralogical characterization, and concentration of the tin-bearing minerals. The tin mineralization consists of cassiterite (sNO2), which occurs as grains disseminated in a greisen (quartz-mica) matrix. A bulk sample from the largest and best-developed greisen vein exposed at Ketchem Dome contained 0.51 pct sn. Concentration of the cassiterite by gravity table methods resulted in a product that contained 56 pct of the tin at a grade of 41.4 pct sn. The mineralization exposed at Ketchem Dome is typical of greisen found in the area and elsewhere in interior Alaska." - NIOSHTIC-2 NIOSH no. 10006027

National Institute for Occupational Safety and Health