Sillimanite



Long (8-10 cm), tapering, spindle-shaped crystals of pale tan sillimanite in parallel alignment, lying flat within a foliation plane in a microcline-biotite-quartz gneiss matrix. This specimen was collected by John L. Baum, first curator of the Franklin Mineral Museum, during his exploration field work for the New Jersey Zinc Company. Subsequently it became part of the worldwide mineral collection of Wilfred and Mary Welsh, who in 1991 donated their entire collection to the FMM. It now bears catalog number FMM-2207. See also related specimen SIL3a.

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Long (8-10 cm), tapering, spindle-shaped crystals of pale tan sillimanite in a microcline-biotite-quartz gneiss matrix

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Identifier: SIL2a
Locality: Owens, north of present-day McAfee, in northern Vernon Township, along the western base of Pochuck Mountain, near the intersection of Owens Station Road (County Route 642) and Lake Wallkill Road. The exact locality is unknown, but this area is about 16 km north-northeast of Franklin.
Specimen size: 16 x 14 x 2.5 cm
Photo credit: Earl R. Verbeek