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- Oreamnos Lake, Sawtooth Batholith, Boise Co., Idaho, United States
- SmCabinet 8x5x4cm
- pegmatite mineral
The Sawtooth Batholith is a shallowly emplaced granite pluton dating to Eocene(45Ma). Miarolitic cavities contain pegmatites containing smoky Quartz, Orthoclase, Albite, and Zinnwaldite. This is an excellent example of these pegmatites, which exhibit the transition from equigranular granite to pegmatite. The photos show how small, 1-3mm, granite grains with graphitic growth phases into larger crystals grown towards the center of the cavity.
The smoky Quartz crystals are 5-12mm and look to be paragenetically first to crystallize. Second to crystallize were the pink Microcline & Topaz crystals and last are the Zinnwaldite. The Topaz are waterclear and are about 4mm.