{"product_id":"lake-superior-agate-stone-of-endurance-and-earth-s-fire","title":"Lake Superior Agate — Large Banded Specimen, Iron-Red Chalcedony, 1,288g (2.84 lb) — Field Find","description":"\u003cp\u003e\u003cstrong\u003eTHE FIND\u003c\/strong\u003e\u003cbr\u003eA Lake Superior agate — 1,288g (2.84 lb) of banded chalcedony with the iron-red, orange, cream, and brown layering that makes Lake Superior agates among the most recognized and collected regional stones in North America. At nearly three pounds this is an anchor piece: substantial enough to command a shelf, complex enough to reward looking. Layer after layer, the bands record changing conditions during formation. Every line is geological.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWHAT WE KNOW\u003c\/strong\u003e\u003cbr\u003eLake Superior agates (LSAs) are banded chalcedony specimens with a specific and well-documented geological origin. They formed approximately 1.1 billion years ago during the Midcontinent Rift — a period of intense volcanic activity when lava flows repeatedly covered what is now the Lake Superior basin. As the lava cooled, gas bubbles created vesicles (cavities) in the basalt. Silica-rich hydrothermal fluids later infiltrated those cavities and deposited successive layers of chalcedony on the cavity walls. The characteristic red, orange, and iron-rich banding of Lake Superior agates is produced by hematite (Fe₂O₃) — iron oxide — incorporated into the silica during deposition. The source of the iron was the surrounding iron-rich basaltic rock. During the Pleistocene (the last ice age), glaciers advancing across the Lake Superior region eroded the volcanic host rock and carried the agates — which are harder and more resistant than the basalt matrix — hundreds of miles from their original formation sites. They are now found in glacial till, gravel bars, and lake beaches across Minnesota, Wisconsin, Michigan, and into Iowa and South Dakota. The exact locality of this individual specimen has not been independently verified. Weight: 1,288g \/ 2.84 lb.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eTHE STORY\u003c\/strong\u003e\u003cbr\u003eBefore anyone found it, the stone had already traveled. It had known heat beneath an ancient landscape — basalt cooling around a gas bubble a billion years ago. It had known silica-rich water moving through that bubble over millions of years, depositing one thin layer at a time. Then came the ice. Slowly, the glaciers carried it out of the volcanic rock that formed it and across the landscape, depositing it in gravel when the ice finally retreated. When the glaciers were gone, the agate remained — waiting beside a northern shore for someone to notice the history written inside it. The red comes from iron. The layering comes from time. The weight in the hand is both.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWHY WE CHOSE IT\u003c\/strong\u003e\u003cbr\u003eLake Superior agates are genuinely significant collector stones — regional, geologically documented, and visually distinctive. At 2.84 lb this specimen has the size to stand as a statement piece in a serious collection. The iron-red banding is what defines the material and separates it from generic agate — this is a specimen for collectors who understand the difference. One of the most historically and geologically substantiated pieces in the Found in the Field catalog.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eABOUT THIS PIECE\u003c\/strong\u003e\u003cbr\u003eType: Lake Superior agate (banded hematite-rich chalcedony — regional identification; exact locality not independently verified)\u003cbr\u003eWeight: 1,288g \/ 2.84 lb\u003cbr\u003eLocality: Lake Superior region (Minnesota \/ Wisconsin \/ Michigan \/ glacial deposit; exact locality not independently verified)\u003cbr\u003eCondition: Natural specimen — please review photographs for banding, iron coloration, surface, and natural variation.\u003cbr\u003eQuantity: 1 — one of a kind.\u003c\/p\u003e","brand":"Found in the Field","offers":[{"title":"Default Title","offer_id":46980420403385,"sku":"8ULE65","price":250.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0782\/9438\/4825\/files\/4FE83353-C3C2-474D-9184-3B2DFE9BCD7B.jpg?v=1783187107","url":"https:\/\/foundinthefield.store\/products\/lake-superior-agate-stone-of-endurance-and-earth-s-fire","provider":"Found in the Field","version":"1.0","type":"link"}