rare
lightning stone
septarian nodule
The tell
A network of pale cracks filled with a lighter mineral, running across a darker body like lightning or a cracked mud flat.
The cracks formed as the nodule dried and shrank on the sea floor, then filled with calcite. Norwood to Leelanau is the belt.
What it gets mistaken for
- black shale
- limestone
- septarian nodule
- concretion
- turtle stone
The facts
- also calledseptarian nodule
- age~360 million yrs
- where it turns upAntrim belt shores ยท Norwood to Leelanau
- on the chartrare · 250 stickers ever
Put it on the shelf
Every stone on this chart is drawn and kiss-cut at three inches. The rarer the stone, the fewer exist: only 250 lightning stone will ever be printed, then the run is retired.
10% of every order goes to the Roscommon County Animal Shelter.