Pegmatite exposure
Black River pegmatite, Republic, Marquette County, Michigan, USA
Here is a photo of the pegmatite exposure along a snowmobile trail north of Republic, Michigan. Quartz, feldspar, and mica can be observed on the face of the pegmatite. Quartz, feldspar, mica, topaz, fluorite, monazite, columbite, and xenotime can be collected by hacking boulders with a sledgehammer. Minerals of interest include green topaz, ...