CHAMPION MINE SPECULARITE
Fun rock collecting can be had at the old waste rock piles surrounding the Champion Mine at Beacon, just to the west of the small town of Champion, western Marquette County, western UP of Michigan.
The Champion Mine exploited the Negaunee Iron-Formation (upper Menominee Group, Marquette Range Supergroup, mid-Paleoproterozoic, 2.11 billion years (or 1.874 b.y.), and the waste rock piles in the vicinity have beautiful, sparkly-silver specularites (aka specular hematite schist - rocks dominantly composed of specular hematite/micaceous hematite - Fe2O3) all over the place. Specularites are the result of moderate metamorphism of iron formation (the full story is much more complex). The rocks here include specularite, quartzitic specularite, and specularitic quartzite. Some samples are moderately magnetic.
Specularite (close-up) from the Negaunee Iron-Formation (2.11 b.y.) at Champion Mine, Beacon, UP of Michigan, USA.
GPS of rock pile: 46° 30.435' N, 87° 59.035' W.