Lake Superior Agate

Locality: Minnesota, USA

Around 1.1 billion years ago, a great rift opened up in what is now the central USA, pouring out thousands of lava flows. The basalt from this event can be seen along the shores of Lake Superior. "Lakers" were formed when quartz-rich groundwater solutions crystallized into concentric bands of chalcedony in gas pockets of this ancient basalt. When glaciers advanced and retreated through the Lake Superior basin, they spead lakers wherever they went. The most common type is a fortification agate with its eye-catching patterns, usually red and white.


This beauty weighs over 1.5 lbs !



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