Interestingly, the state gemstone of Minnesota is Lake Superior agates. These curiously looking rock formations have captivated people for a really long time. What is even more surprising to know is that in 1969, the Minnesota Legislature declared Lake Superior agate as the official state gemstone. Despite its love and craze among netizens, people are still uninformed about how are Lake Superior agates formed and whether is it illegal to pick agates. Well, this article will help you out with these and more questions.
Table of Contents
1. What Causes Agates to Form?
An agate crystal forms in cavities of other rocks in acidic to neutral environments. Silica-rich groundwater accumulates in the pores of rocks over thousands of years. This leads to the formation of agates. These chalcedony veins mainly develop in the voids of igneous and fat-rich igneous rocks.
2. How are Lake Superior Agates Formed?
Lake Superior Agates forms by the Lava flows. When the surrounding volcanic rock worn away by erosion or glacial stripping, the agate is released from the lava and moved to other locations. As the lava solidifies, water vapor and carbon dioxide trap in the solidified flow.
This forms a pore-like texture (i.e., millions of tiny bubbles). The groundwater then carries iron, silica, and other dissolved minerals through the trapped air pockets. These concentric bands called are the chalcedony or encrusted agate. They are fine-grained quartz-rich groundwater solutions deposits.
This sums up how are Lake Superior Agates formed. See What does Real Gold Look like in Rock?
3. Are Lake Superior Agates Rare?
Yes, Lake Superior agates are rare. It is an iron-colored agate found on the shores of Lake Superior. Its wide distribution and iron-rich bands reflect the geological history of this gem in Minnesota, Wisconsin, Nebraska, Iowa, Kansas, and Michigan.
Lake Superior Agate is known for its rich reds, oranges, and yellows. This color palette is caused by the oxidation of iron. The iron mined from the stone has provided the pigment that gives the gem its beautiful color palette. The concentration of iron and the amount of oxidation determine the color within or between the bands of the agate. There can also be bands of white, gray, black, and beige.
4. Are Lake Superior Agates Hard to Find?
Yes, Lake Superior agates are rare. It is an iron-colored agate found on the shores of Lake Superior. Its wide distribution and iron-rich bands reflect the geological history of this gem. You can find them in Minnesota, Wisconsin, Nebraska, Iowa, Kansas, and Michigan.
Lake Superior Agate is known for its rich reds, oranges, and yellows. This color palette forms by the oxidation of iron. The iron mined from the stone provides the pigment giving the gem its beautiful color palette. The concentration of iron and the amount of oxidation determine the color within or between the bands of the agate. There can also be bands of white, gray, black, and beige.
5. Why are there so many Agates in Lake Superior?
You now know how are Lake Superior agates formed. Now, let us take a look at why there are so many. There are so many agates in Lake Superior because Laurentia started to split apart. This was due to the shifting of the tectonic plates, and lava started to erupt through the cracks in the crust. Gas pockets were trapped in the permeable rock when the lava hardened.
With time, silica and element-rich water drip through the bedrock, filling these openings. That formed striated bands of various minerals that piled on top of one another. The vibrant stripes in agates are created by these layers. The foundation of the Earth’s crust around most of Lake Superior is part of the Canadian Shield. It is from the giant core of North America. This massive mass is made up of rocks that were formed during the Precambrian period. That is, from the beginning of the Earth’s formation about 4.7 billion years ago to a time only 545 million years ago.
6. What’s the Biggest Lake Superior Agate Found?
The Biggest Lake Superior agate is 110 pounds, which is equal to the size of an adult human.
Each band of agate comes from a different mineral and most agates are 99% microcrystalline quartz. When you see orange, rusty, brick-red bands, you see rusted iron. Agate is much harder than the rock from which they form. The softer basalt and rhyolite around them erode away. This breaks apart and gets washed up on our beaches.
Most of Lake Superior’s agate began to form about 1.1 billion years ago by bubbles of sulfur and carbon dioxide in the lava that formed the landscape. These bubbles slowly filled with layers of other minerals that form the agate we see today. (See How many Crystals are there in the World?)
7. What’s the Biggest Agate ever Found?
The largest agate weighed 61,090.2 kg (134,680.84 lb.). It was verified at an event organized by the Fuxin Municipal Government Development and Reform Commission. The event took place in Fubin City, Liaoning Province, China on October 25, 2009.
Onyx is 22.62 cubic meters (798.82 cubic feet). It measures 2.71 m (8 ft 10.69 in) from top to bottom, 5.09 m (16 ft 8.39 in) from left to right, and 4.69 m (15 ft 4.65 in). Cross back and forth.
8. Which State has the Most Agates?
Now that we have already discussed how are Lake Superior agates formed. It is time to look at the places with the most agates. Oregon, Washington, Idaho, and Montana are the main sources of agates in the United States. But they are found all over the world. Mostly, in the cavities of ancient volcanic or lava rock.
9. What is the Rarest Form of Agate?
Although there are so many agates in Lake Superior, some of them are extremely rare. The rarest form of agate is called the Plentitude Stone. It is known to be the most valuable form of agate. Must see What Are Some Yellow Stones?
10. Why are Agates So Special?
You already have the answer to how are Lake Superior agates formed. Here is why Agate is special:
- Agate can be the perfect stone for your collection or home decor.
- It includes sealed crystalline silica.
- It forms rich color with banding patterns.
- It is distinguished by fine grains.
- It is primarily chalcedony, a type of stone that looks like wax and is transparent.
11. Is it Illegal to Pick Agates in Minnesota?
No, it is not illegal to pick agates in Minnesota. Many agates are found in gravel pits and along the banks of rivers and streams. You must get permission from the private owner to hunt in the gravel pit. Because some owners will not permit it due to the risk of injury. Rock picking is not permitted in state parks and state natural and science areas. (Also Read: 10 Types of Beach Stones)
