Description: Radiant Minnesota Thomsonite #5 Huge "eyes" easy to extradite. Lake Superior Thomsonite In Matrix, Measures about 7 inches long, and 3.25 x 3.5 inches. From an old collection on the North Shore of Lake Superior, Minnesota. The World’s Most Colorful Opaque Gemstone Thomsonite (also known as lintonite). Its rarity is due to the fact that this gem variety is only found on a six-mile stretch of “North Shore” beach. Analyzing Thomsonite: Formed During a Rifting EventThe colorful Minnesotan version of this zeolite was born out of a massive continental rifting event that started over 2 billion years ago. Back in the Proterozoic Era, the interior of the ancient North American Plate began to split apart due to magma erupting from a long, boomerang-shaped fissure. As the crack widened, massive outpourings of runny basaltic lava flooded the land. The resulting rock became the foundation for the Great Lakes, formed some of the most wonderful geology around, and produced several types of ore deposits and unique gemstones. Before the split was complete, it suddenly failed. Although the tectonic extension ceased, hydrothermal fluids circulated through the basalt leaching, iron and other elements from it. The dissolved elements precipitated out into the gas voids (vesicles) left behind by the degassed, cooling molten basalt. Along with thomsonite, other notable minerals found in vesicles along the North Shore is the lovely, banded Lake Superior agate. Thomsonite crystals grow within the vesicles as vertical, needlelike bunches from a central “seed”, and proceed to grow outward. Faint, fibrous patterns can be observed in many of the stones. The fibrous habit, combined with multiple colors, gives rise to another defining characteristic of thomsonite: its concentric “eyes”. The best thomsonite gems contain multiple eyes (like these!) and formed around multiple “growth seeds”, that can stand alone or grow into each other, much like cave stalactites. The fractured basalt of these rocks I have listed make extracting the Thomsonite with simple pry tools quite easy. I will be listing more in the next few days, and will combine shipping and handling to give you a generous price break on shipping. I package and ship the same day payment is made. Thank you!
Price: 21.99 USD
Location: Grand Marais, Minnesota
End Time: 2025-02-06T03:35:52.000Z
Shipping Cost: 10.99 USD
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All returns accepted: ReturnsNotAccepted
Country/Region of Manufacture: United States
