ancient rock is the fossilized remains of Stromatolites, stony algae colonies
that built up layers and sometimes whole reefs. Now, replaced in sedimentary
rock, the beautiful filaments and layered polyps are one of the earliest
life forms preserved today. At over 2 billion years old, this primitive
species is often credited with providing our oxygen rich environment we
I find it fascinating that we can find and use the Banded Iron Formations these creatures laid down, layer after layer in some ancient ocean. Stromatolites are thought to have oxidized the iron rich oceans in which they lived in to iron-rich sediments, that settled on the ocean floor. Their by-product was… Oxygen! Mary Ellen Jasper and Jaspilite are excellent examples of this whole process!
Mary Ellen is a striking rock. Brilliant, intense colors are sometimes very well replaced with micro crystalline quartz that is very hard at a mohs 7 or more in the best specimens. It can be polished to a glass finish with a magnificent shine. Quality Hematite veins also polish to a metallic highly reflective surface.
It takes its name from the Mary Ellen Mine in St. Louis County, Minnesota, where it was first discovered. Rumor has it, the miner who staked out the Mary Ellen claim named the deposit after his girl friend!
From time to time
I’ll find some quality Mary Ellen in the glacial till of the Lake Superior
region. I'll polish, photograph and share the best samples of this unique
rock from Northern Minnesota!
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