Agates are formed from silica solutions filling gas bubbles in lava rocks, creating bands of color. The best time to find agates in Michigan is after a storm. Popular Michigan agate hunting locations ...

Thanks to fire and ice, treasures abound. This summer, agate collectors are on the hunt in eastern Minnesota and western Wisconsin, searching for rocks that can fetch as much as thousands of dollars ...

The elusive Lake Superior agate. Rockhounds scour Lake Superior’s shoreline for these rare banded beauties—from the western reaches of the Keweenaw Peninsula to the U.P.’s easternmost Whitefish Point.

SAUK RAPIDS, Minn. -- For Lyndon Johnson, treasures can be found anywhere -- one just has to train his or her eye. "I know when to look and where, and where to look when," Johnson said with a smile.

I think I have always been enthralled with rocks, having the rock hammer my mother bought for me more than 60 years ago hanging on the "birdroom" wall of my backwater cabin. And, even though one would ...

Add Yahoo as a preferred source to see more of our stories on Google. Known for their colors and patterns, collectors are often amazed at agates that turn up on Upper Peninsula lakeshores, with some ...

The geochemistry of agate and chalcedony in volcanic rocks represents an intricate record of silica precipitation and crystallisation processes occurring under variable thermal and chemical conditions ...