Chlorastrolite is Michigan's state gem. Mainly found along the beaches of the Great Lakes and in Isle Royale National Park. These stones are most commonly pebble-sized bluish-green in color with a star pattern of crystals that resemble a turtle's shell, most commonly called greenstone, a variety of the mineral pumpellyite. Chlorastrolite pebbles often contain other minerals that give them color variations, such as the pinkish hues of prehnite.
Agate is a variety of quartz gem found on almost any beach in Michigan, but mostly along the shores of lake Superior in the Upper Peninsula. They vary in color but their defining feature is their concentric banding.
Hematite is an iron ore that is black or rusty reddish black in its raw form but often a shiny black in its polished gemstone form. You can find these stones in old mining dumps in Michigan, and they also can be found along the shores of Lake Superior.
Jaspilite is a banded iron formation also known as banded ironstone. It occurs in the knolls between the cities of Negaunee and Ishpeming in the Upper Peninsula, predominantly on a hill called Jasper Hill. Jaspilite stones, consisting of alternating bands of light red jasper and hematite, represent some of the oldest rock formations in existence. They were created when banded layers of iron were common in Earth's crust, over 3,500 million years ago.
The Best Central UP Rock Picking Beaches The shoreline from Whitefish Point heading west to Grand Marais offers some of the best agate finding opportunities around Lake Superior. These are some of the most accessible beaches, but are the most hunted. You'll have better chances by driving many miles down the back roads and doing some hiking. There are many isolated beaches that produce fine specimens.
Lake Superior State Forest Beach
From Grand Marais, go east on Highway H58 about 10-12 miles. The beach can be accessed from the campground and further down the road (H58) you'll find several parking areas not far from the beach. Nice specimens can be found here. If you can continue driving east you'll reach Muskallonge State Park.
Muskallonge State Park Beach, Deer Park
There's at least 3 miles of accessible beach but is very remote. From Grand Marais, you'll have to retrace your path 25 miles back to Newberry.
Whitefish Point Beach
You'll need to walk several hundred yards west of the Lighthouse to run into some good rock picking territory. You can even drive along West Wild Cat Road to access some good rock beaches even further west of the point.
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