Minnesota has had the Lake Superior Agate as our state gem since 1969.
The late Mrs. Jean Dahlberg, long-time rock hound and ardent fan of the agate, testified before the state legislative committee considering the bill. She knew how perfect the Lake Superior agate was for the state gemstone.
Other options for our state gem then were:
- brazen red Binghamite
- yellow Silkstone
- Thompsonite (zeolite mineral found only in Minnesota)
The agate was ultimately chosen for a few reasons:
The agate reflects many aspects of Minnesota. It was formed during lava eruptions that occurred in our state about a billion years ago. The stone's predominant red color comes from iron, the major industrial mineral in our state. Finally, the widely distributed agate reveals the impact of glacial movement across Minnesota a mere 10,000 to 15,000 years ago.
If you are searching for these special rocks yourself the best places to look for them are the public beaches along Lake Superior. It is the "Lake Superior" agate after all. Closer to home, agates can be found along gravel roads and in rocky areas all around Central Minnesota. Many agates are found in gravel pits and along the banks of rivers and streams, be sure you have permission from landowners if you wish to pick in a pit or along a stream on private property.
- Band planes along the rock indicating the gem's layers
- Rust-red and yellow iron oxide stains
- Translucence, hold the rock up to a light source to check for translucence
- Glossy or waxy appearance, especially on a chipped or broken surface
- A pitted texture on the outside
Thinking of picking up a cool agate on your hike through a state park as a memento? Think again. Keep in mind, taking things from Minnesota State Parks is not allowed. The old saying is "take nothing but pictures, and leave nothing but footprints". If everyone who visited a state park took a rock or stone, the whole place would be pretty picked over.