Minnesota iron industry is built on this Banded Iron Formation. This ancient
rock is sedimentary. Thick layers of sediment built over time at the bottom
of an ancient ocean.
Over 2 billion years ago, Stromatolites, stony algae colonies, are thought to have oxidized the iron rich oceans, resulting in iron-rich sediments, that settled on the ocean floor in layers. This process also produced oxygen for the oceans and atmosphere.
In Northern Minnesota, Jaspilite is an excellent example showing the classic brilliant bands of red Jasper alternating with the silvery metallic of the Hematite. Itís striking when polished and occurs in a variety of patterns.
time to time Iíll find some quality Jaspilite in the glacial till of the
Lake Superior region. Iíll polish, photograph and share the best samples
of this unique rock from Northern Minnesota!
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