Minerva No. 1 Mine, Cave-in-Rock, Illinois

The Minerva mine was located in Illinois and is part of the Illinois/Kentucky fluorospar district. It was the largest orebody in that district. Discovered in 1940 it was mined off and on until 1996. Many spectacular specimens have come from this mine over the years - including fluorescent species such as fluorite, sphalerite, calcite, dolomite, strontianite, and witherite. The mine has been reclaimed and all the buildings, the adit, and settling ponds are gone. All that is left is many acres of what appears to be gravel "pastures" and small hills. The area is becoming overgrown with small trees and grasses but is still quite accessible.

It is about a three hour trip to Cave-in-Rock from my house in middle Tennessee. The unofficial "Middle TN Fluorescent Mineral Club" got together one weekend in the fall of 2011 and made a day-trip to this famous mine. Five ardent glow hounds descended on Minerva and proceeded to light up the grounds with our UV lights. The resulting finds were wonderful, and a great time was had by all.

ferry ride with cars on top

To get to Minerva from Tennessee we had to cross the Ohio River via the Cave-in-Rock Ferry. This ferry provides service across the Ohio River between IL 1 and KY 91 at Marion KY (another famous locale in the KY/IL fluorospar belt - see my trip report on the Colombia Mine).

The ferry only operates until 9:50 pm so we had to be sure to make it back in time or it would mean several extra hours added onto our return trip.

Once across the river you're in the town of Cave-in-Rock. It's a short ride along IL 1 to the turnoff to Minerva (Lamb RD). Just a mile or so down this dirt road you'll start to notice a gravel "field" off to the left. We just turned into one of the ATV entries (a high clearance vehicle is recommended due to the big rocks strewn about). The area is quite large and has been bulldozed flat. There are no gates or signs, and it appears people use the area for ATV trails, so we just moseyed on it and started hunting for glow rock.

a view of trees

It's easy to pull your truck up to the edge of the field and simply get out and start hunting. We all brought a good assortment of tools but the most useful ended up being pry bars to loosen large boulders out of the gravel, and sledgehammers to break the boulders into manageable pieces.

a pile of rocks from a busted boulder

There are several stream beds crossing the property and they seemed to be the most productive. Large boulders of calcite and fluorite were washed out of the banks and easy to get to. I'm pretty sure the flat gravel fields are hiding large pieces of ore but it would take some serious work to dig down to get them - easier to allow Mother Nature to do the job for us.

We explored for the rest of the afternoon, busting rocks for examination later in the evening. Piles of potentials were made and a few nice crystal pieces were found. Evening came around 6:30 and we started exploring in earnest. Pretty soon it became evident that we had already identified all the fluorescent species we were going to find earlier in the day; a complete search of the grounds in darkness did not reveal anything new. So we high-graded our haul, packed up the trucks and headed back to the ferry (we did not want to be stranded on this side of the river).

people by a truck

It was a great trip with some really good finds. With a little work (actually a lot) perhaps more can be found by digging and exposing more boulders. Below are a few pictures of the minerals we found and our assumed identifications...