Genoa, Ottawa Co., OH
Sept. 15, 2007
On Saturday, September 15 the Friends of Mineralogy, Midwest Chapter made a field trip to the GenLime Quarry in Genoa, OH. Since we were to meet at the quarry at 9 AM Eastern time, I would have had to leave my house before 5 AM Central time to get there. Not being much of a morning person, I opted to leave on Friday afternoon, and spent the night in Perrysburg, OH, just off the Ohio Turnpike, Exit 71. From there it was only 7 miles to the quarry: 2 traffic lights South on Rt. 420, then left on Rt. 163 to Genoa. The quarry entrance road is on the South side of Rt. 163, on the East side of Genoa. It’s marked by a very obvious sign.
In the parking lot near the quarry office we were met by Gary Elliott, the quarry manager. We were also joined by a group of geology students from the University of Michigan. Gary told us a bit about the quarry and gave the mandatory safety lecture. He then led us in convoy down into the quarry to a bench just above the bottom, which he had selected for good mineralization. The road down was exceptionally smooth for a quarry. It was actually better than some of the county roads in my area!
In the area selected, Gary had even supplied a port-a-pot!
The minerals found here are mainly celestine and fluorite. The celestine is in white blades, found in large pockets in the dolomitic limestone. It was frustrating to see some basketball-sized pockets that couldn’t possibly be removed without damage to the delicate celestine crystals.
The fluorite found here is brown cubic crystals, and massive. It was exceptionally plentiful this day.
Most of it came from the large boulders seen here, and out of the hole under them. The hole at the collector’s feet went in about 10 feet.
The most interesting pieces were combinations of fluorite and celestine. Both fluoresce, with the brown fluorite fluorescing white and the white celestine fluorescing brown.
There were also nice calcite crystals to be found, some poor pyrite, and extremely scarce galena.
Just to the right of the area shown in the above picture I found some celestine that was in bluish tabular crystals. I was informed that this material came from Clay Center, about 3 miles North of Genoa, and had been dumped there. This is a practice I generally strongly discourage, since it can lead to mislabeling. In this case, knowing where it came from, I was happy to pick up a couple of flats of nice crystals.
For the record, the co-ordinates of the quarry are 41 deg. 30.150’ N, -83 deg. 21.197’ W.