Lake Superior Agate Long Sleeve

About 1.1 billion years ago, the middle of North America tried to split apart, and lava poured out along what's now Lake Superior. Gas bubbles got trapped as it cooled, and over time groundwater filled them with silica and iron, one thin band at a time. Much later, glaciers ground the old lava down and scattered the agates across the region.

That's why people walk the Upper Peninsula shoreline from Grand Marais to Whitefish Point staring at their feet. You're looking for a rust-red pebble with a waxy shine that lets a little light through. Most of the time it's jasper. Once in a while it isn't.

We drew ours the way the old field guides did: one stone, cut in half to show the bands, labeled underneath. On the front there's just a small logo on the chest. The shirt is garment-dyed for a soft, broken-in feel, in Blue Jean or Light Green, with a relaxed fit.

One for the rock hounds: the Lake Superior agate is Minnesota's state gemstone. Michigan's is the Isle Royale greenstone. The glaciers didn't check the map.

Details

• 100% ring-spun cotton, 6.1 oz
• Garment-dyed, so each shirt's color varies a little
• Relaxed classic fit
• Ribbed cuffs and double-needle hems
• Small logo on the chest, agate print on the back
• Colors: Blue Jean and Light Green

Care Wash cold and tumble dry low. Don't bleach, iron on low, and don't dry clean.