One of the more recent discoveries in the Keweenaw Peninsula are very rare copper included agates from the Kearsarge Lode. These little beauties are banded agates where some of the banding is replaced by native copper.
This makes them very desirable for distinctive jewelry.
These agates require hard labor to recover. I have seen holes on the mine dumps excavated over 8 foot deep where little or nothing is found, but sometimes these agates are found in abundance in one small area. It takes a lot of luck and work to find a good one. You can find these agates with a metal detector but you may also be overwhelmed with false “hits” as you are searching in a copper tailings pile. I just leave the detector and dig, then check the pile I’ve sorted with the detector to see if I missed anything.
These copper/agates are not considered as Lake Superior Agates, but are agates from copper mines, according to my friend Jeff Anderson.
Jeff and I agree that the copper entered the agates while they were being formed. It is interesting that at a specific depth
the copper coming up as super heated steam met the silica materials coming down and filled the same vesicles.
Seldom are these little agates over a couple inches which seems to indicate they formed in smaller vesicles in the amygdaloidal basalt. In general the smaller the vesicle, the closer to the surface so these agates were not formed at great depths.
The agates are commonly light pink and often include blue/green, but I have not seen any of red as is common in the Lake Superior Agates.
This geology is very interesting, and I know there is some research being done on these unusual agates. Rumors are that there also may be an article in regards to them in a major magazine in the near future.
The agates have a dark skin and you just do not know what you have until you cut these agates in half. What a great surprise when you find something like the pendant stones I’ve posted in this blog.
I personally know of no other web site that has any copper replacement agate jewelry except this one. The prices of these agates is based on the rarity and difficulties in finding them. They are much more difficult to find than the elusive Isle Royale Greenstone.