Ilmenorutile locality, Tulare County, California, USAi

Regional Level Types
Ilmenorutile locality	- not defined -
Tulare County	County
California	State
USA	Country

A discovery of large, well-formed ilmenorutile (Nb-rich rutile) crystals was made by three collectors in 1965 somewhere high in the southern portion of California’s Sierra Nevada. The trio made a pact never to reveal the location of their discovery. The eldest of the three, Charles Bishop, died in 1968 at the age of 76. In 1988 his collection, including many of the ilmenorutile specimens found by the three collectors, was donated to the Natural History Museum of Los Angeles County. The matrix of the specimens is a very coarse-grained intergrowth of smoky quartz and albite, with lesser amounts of muscovite, phlogopite and spessartine, clearly indicative of a pegmatite deposit. Charles Bishop had labeled the specimens “Nine Mile Canyon, Tulare County”. Nine Mile Canyon transects the eastern escarpment of the Sierra Nevada just north of the southern border of Inyo County, terminating at the crest of the Sierra, which also corresponds with the boundary between Inyo and Tulare counties. Above the head of Nine Mile Canyon, near the crest of the Sierra, there are several pegmatitic feldspar deposits that have been mined in the past. The only remaining member of the collecting group, Bob Raduenz, has confirmed that the three collectors ascended into the Sierra via Nine Mile Canyon Road; however, he claims that the trio hiked for several days before encountering the ilmenorutile deposit. Based upon existing evidence, it seems very likely that the ilmenorutile locality is in the high Sierra of Tulare County. Most, if not all, of the ilmenorutile specimens from this deposit that have reached the collector market have come from the collection of Bob Raduenz.

EDS analysis of the rutile provides the composition (Ti0.78Nb0.13Fe0.09)O2.

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