Gitche Gumee Handcrafted Jewelry
Lake Superior Agate Pendants & Jewelry
All About Lake Superior Agates
Welcome to Gitche Gumee Handcrafted Jewelry and my information on Lake Superior Agates. Over a 1.2 billion years ago, agates were formed in North America through iron-rich lava flows. These flows became exposed throughout the shores of Lake Superior - mostly along the north and southern shores. These lava forms created the ideal conditions for Lake Superior Agates! The makeup of the banding consists of iron, silica and other minerals. Groundwater also had a hand at play and the quartz rich water deposited bands of fine quartz within the vesicles (empty pockets where lava solidified - trapping water vapor and carbon dioxide).
Lake Superior Agates are commonly rich in reds, oranges and yellows. This is caused because of the oxidation of iron. These incredible bands of colors can also include white, grey, black, tan, peach, along with others that are more rare.
Lake Superior Agates are semi-precious stones. Fine sharp banding of an agate increases the worth of the agate. When cut, ground, and polished, the banding and colors are breathtaking!
Lake Superior Agates come in all sizes, but large ones are rare. The most common is the fortification agate - rich with parallel banding that follows a pattern and connects back to the beginning. Sometimes this banding is interrupted because of fracturing throughout the course of its existence.
If you find a large agate, please seek advice on cutting and "face polishing". Sometimes agates of over 2 pounds should be left as is because it is more valued by collectors in their found state.