Minnesota Thomsonite

Notes specific to this specimen: Cut and polished matrix piece from the old Thomsonite Mine along the North SHore of Lake Superior about five miles southwest of Grand Marais, Minnesota.  Many colorful small vesicles filled with gem Thomsonite.

Size: 4″ x 2″ x 1″

Name / Species: Thomsonite
Age: Mesoproterozoic Era, 1.1 billion years
Unit: Terrace Point Basalt
Site: Alley Agate Shop Thomsonite Mine Cook County, Grand Marais, MInnesota
Collected: 1981
Collected by: Jon Kramer

Documentation: This authentic fossil specimen comes with a Certificate of Authenticity and Origin. In addition, an attractive and informative display card accompanies the specimen.

Notes specific to this specimen: Rare dense accumulation of nodules in matrix, from what was known as a “Bonanza” zone in the “Pink Pit”.  Colors varied from pit to pit in the mine.  The Pink Pit was the largest and most accessible pit and was right in the center of the Thomsonite Mine, adjacent to the parking area.  On rare occasions we would mine into a “Bonanza” which was a zone especially dense with nodules.  This piece has a sawn flat bottom with smoothed and polished front and natural rough back. It has three very bright, large nodules exposed with high polish on the front face.  They could be removed and cut for jewelry.

Size: 3″ x 4″ x 1.5″

Name / Species: Thomsonite
Age: Mesoproterozoic Era, 1.1 billion years
Unit: Terrace Point Basalt
Site: Alley Agate Shop Thomsonite Mine Cook County, Grand Marais, MInnesota
Collected:
Collected by: Jon Kramer

Documentation: This authentic fossil specimen comes with a Certificate of Authenticity and Origin. In addition, an attractive and informative display card accompanies the specimen.