London, England/london2G-010
Previous | Home | NextThis is the original sample of columbite analyzed by Hatchett, who discovered niobium (columbium) in 1801. By the kind courtesy of the Natural History Museum in South Kensington, both a photograph and a chemical analysis of this sample has become available to the authors. The Museum's analysis of this sample gives a metal content of 55% niobium, 26% tantalum, 15% iron, and 4% manganese. This sample of columbite was originally furnished by "Governor Winthrop of Massachusetts" and was reputedly from "New London [Connecticut]," the home of Winthrop, but columbite is not found in that vicinity; local geologists agree that Winthrop's sample was probably from Middletown, Connecticut.
Chemical analyses of other Connecticut samples of columbite from the Middletown region (by the authors of "Rediscovery") show ranges of 55-50% niobium and 15-26% tantalum (and iron 10-15%, manganese 5-10%).
Wollaston subsequently studied this sample, but owing to the chemical similarity of niobium (discovered by Hatchett) and tantalum (discovered by Ekeberg {LINK:Uppsula204 old chemistry building} he confounded the two elements. The clear differentiation between niobium and tantalum was later performed by Heinrich Rose {LINK: Berlin090} and Marignac {LINK: Geneva002}.
Photograph, by the kind courtesy of the Natural History Museum, South Kensington, London.
