• Specimen Number

  21

• Description

  Fractured large cobble of pink granite dominated by quartz and alkali feldspars with shiny muscovite.  Smooth surface of cobble suggests it's very strong and far-travelled.

• Classification

  Igneous. Plutonic. Granitic. Granite.

• Location & Occurrence

  Unknown. Nothing distinctive and no report from the state survey. This is almost certainly a glacially transported stone. We have no idea where in the state it was collected from, which means it could have come from the eastern provenance of the Superior Lobe or the western provenance of the Des Moines Lobe.

• Geological Age

  Precambrian (?)

• Geoheritage

  This stone may be the most difficult to source. Likely a far-travelled cobble from the Canadian Shield. The smooth surface suggests it was a lake shoreline cobble.

• Links

  Link to State Geological Map from USGS.  Link to Minnesota Geological Survey.

• Other

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