Lake Superior agate

The Lake Superior agate is a type of agate stained by iron and found on the shores of Lake Superior. Its wide distribution and iron-rich bands of color reflect the gemstone's geologic history in Minnesota. In 1969 the Lake Superior agate was picked by the Minnesota Legislature as the official state gemstone.

 References  
 Minnesota's State Gem: The Lake Superior Agate

Category:Gemstones
Category:Quartz