If you plan to ask Scott Wolter about Lake Superior agates, make yourself comfortable. The rock hound has a lot to say.

It takes time to explain how agates began forming more than a billion years ago, as ice sheets followed the flow of Lake Superior and pushed these rocks into most of Minnesota and much of Wisconsin. It also takes time to amass one of the country's most impressive agate collections.

Wolter, a geologist and master storyteller, says there's still a lot to learn about Minnesota's state gemstone and those trademark bands of color. Were the layers formed one at a time, or did they separate internally? No one really knows, he says, which isn't easy for a scientist to admit.

"Agates are magical things," he says. "They still hold secrets and they aren't giving them up yet."

Wolter has been collecting agates for 40 years, a passion that started as a college student in Duluth and hasn't waned. Over the years he's mined gravel pits, beaches and the bottom of Lake Superior looking for agates, and turned it into a lucrative hobby that, over the years, his whole family would enjoy. "We've made so many memories," he says.

He's also published books and helped make the hobby accessible. The payoff is seeing young people discover collecting, and a new generation becoming smitten with agates.

"The deeper you look, the more you see"

Some rocks need to be cut and polished to reveal their true beauty, Wolter says, but others are "stunning" in their natural state, which the geologist in him favors. (Most in his collection are in their natural state.) "We're just the caretakers of these for a short time," he says. "Nature did that, and we can't improve on that."

The best place to see agates

It's fitting that the Agate Capital of the World is in Moose Lake, Minn., a stone's throw away from Lake Superior. On July 13 and 14 the town will host the 50th annual Moose Lake Agate Days, which Wolter says is the place to be for anyone who wants to buy, sell, trade or just see good Lake Superior agates. Many of the best collectors, including Wolter, will be there. mooselakechamber.com