Black Mountain and the Copper Mountain District
Attendees: Bill Chirnside (and his dog, Prospector), Donna Hughston, Pete Modreski, Steve Swanson, Brian and Wendy Mitcheltree, Bob Loeffler, Earl Stewart and several Wyoming clubs members.
This trip took us to two general areas: Black Mountain and the Copper Mountain Mining District. Several clubs, at least one of them from Wyoming, were involved.
After a long drive from Denver, we all met near the Black Mountain location at 1pm on Thursday afternoon. Bill, our leader, led the way to the digging area. Spodumene and tourmaline have been found here and this is the only known spodumene pegmatite in Wyoming, according to the Mineral News newsletter (volume 15, number 5 [May 1997]). There were 3 main quarry pits that I saw. Each were quite small so the commercial mining up here wasn't extensive. The middle pit seemed to yield the most specimens. We found green and gray spodumene and black and green tourmaline in it. They didn't have any terminations and were opaque because they didn't grow in miarolitic pockets that we normally see in the pegmatites in Colorado. If there were pockets, they were really small.
That afternoon, we all decided to head for camp. There wasn't a good place to camp near the digging site, so we drove an hour to the Castle Gardens campground. Along the way we saw many antelope which are abundant in Wyoming. The campground was beautiful with neat rock formations and petroglyphs. To our surprise, we found selenite crystals above the campground.
On day two, we drove to the Copper Mountain Mining District where we dug the next two days. In its heyday, it produced such minerals as cleavelandite, beryl, mica, columbite, tourmaline, gahnite, microcline, petalite, spessartine garnet, tapiolite, and copper ores. The first area that we went to was the Whippet #1 Mine (formerly the Bonneville #1 Mine). We found columbite, feldspar, mica and a little bit of blue fluorapatite there. Close by was another prospect (I don't think it had a name) where Steve and Brian found some really nice black tourmaline specimens. We spent a couple hours at these sites and then moved on.
Next up was an old dump and loading chutes where ore was loaded into trucks for transport. The first dump wasn't near any mine or quarry, so it probably came from one of the Whippet mines. We found tourmaline and lepidolite here. The ore chutes were near the Zimmerman Mine which is less than a mile east of the Whippet #1. Poor quality tourmaline was abundant here.
An hour after we played around the old dump and chutes, we drove north to a couple quarries (I don't think they had names). This is where we camped for the next 2 days. Black tourmaline (schorl) and blue tourmaline (elbaite?) specimens were everywhere in these two quarries, although their quality was the same as the other locations on this trip. It isn't gemmy or terminated, but still nice because you can see its crystal structure.
Setting up our tents wasn't very easy because there was lots of sage and cactus in the area. A couple of us set up our tents on the dirt road because it didn't have as much vegetation on it.
Our last digging site was the Whippet #8 Mine (formerly the Bonneville #8 Mine) which was high up the mountain (approximately 7000 ft elevation) near our camp. The main minerals from this mine were petalite, tapiolite, gahnite, beryl, feldspar and spessartine garnet. We found large, opaque blue and green beryl, small tapiolite crystals, microscopic green gahnite and reddish spessartine crystals, and massive white petalite. The tapiolite is a black, metallic, tetragonal mineral with a (Fe,Mn)(Ta,Nb)2O6 composition. Steve found a really nice tapiolite specimen that might be a twin crystal.
Thanks to Bill Chirnside for leading us on this trip. More info regarding the Copper Mountain District can be found in volume 76 (May/June 2001) of Rocks & Minerals magazine.