Clifton & Morenci Mines
Greenlee County, Arizona
June 2008
By Junesse Farley


I know that it's been awhile since I've written a field trip report, mostly because of time. I haven't had the time to write stuff up or to go out into the field much. Mostly that's because the time to go out is when school/chorus/science olympiad/sports/plays, etc. are in session. But this weekend I decided that we had to go out while it was just stupidly hot instead of incredibly stupid-hot or else write off collecting until the fall when the time crunch would be starting all over again. So it was now or never.

Given that the temp. here is already around 109F, I knew we'd have to go somewhere we could reach easily without being too far from the car in case of overheating. For those of you who don't know, people who aren't prepared for the desert can die very easily. Hundreds of illegal immigrants die every year trying to cross the desert. It would also be a good idea to go someplace that we could get to in one day, get to early in the morning without leaving too early and somewhere at a higher elevation so it would be cooler. So I decided to head north of Clifton and Morenci to stop at two sites along road cuts.

We left at quarter to seven and arrived at the first site just north of Clifton by about 9:30. The temp. was in the high 80's which wasn't too bad, but it was right along the San Francisco River which increased the humidity above what us desert rats are used to dealing with. This location is known for its agate which formed in seams and crumbles out of the rock alongside the cut.

On the other side of the road you can scramble along the not TOO steep slope where the rubble from the road cut is piled and see what you can find. My son stayed up on the road while my husband and I clung to the sloping rubble pile, and we tossed up pieces when we found them. Sean's friend searched the bottom edge which was more stable. Call us paranoid, but we didn't really feel comfortable with the kids climbing on the loose rubble. But they also searched the bottom of the cliff face and found some lovely specimens there as well.

Here are some of the agates that we found. Most of the agate is clear or lightly blue, but a lot of it has plumes or mossy inclusions in a number of colors.

My husband found the specimen that is triangular with white and salmon banding in a distinct eye. He's not thrilled with rockhounding, but doesn't want me to go anywhere without him, so we compromise and don't do too many trips. It was really neat that he spotted this piece and was excited about his find.

Most of what we found was free of the matrix, but we did pop out some pieces. While I was scrabbling around, I found this lovely little piece of blue agate on the right that is really a beautiful shade of lavender. My husband was sweet enough to hammer at the matrix for me. It's mighty thin and small but the color is incredible, reminding me of holly blue that I bought a couple of years ago. Then I found a piece that had hints of red swirls – I almost danced for joy when I wet it down and saw these fiery layers appear from beneath the slight haze on the surface. That's the one on the left!

Even though the agate is the main attraction, we also found some nice calcite. These massive pieces are really nice. The one on the right shows a crystal clear section that you can see into for about an inch. The one on the left is really pearly and satiny looking.

This piece has really nice crystals over a bed of chalcedony and some other black-grey charcoal-like botryoidal mineral. I'm not sure, but I think some of these are dolomite crystals as they don't effervesce very well, are striated along the crystal face which is slightly curved. They test out at a hardness of 3 to 3 and a half.

This one we found floating loose in the dirt.

We only worked for about an hour or so, before we started feeling the heat too much (which, in the desert has a habit of steadily and rapidly climbing until late in the afternoon). Actually, I was the one having trouble with the heat, since I've been a bit more sensitive to it ever since a bout w/heat exhaustion about 7-8 years ago, but we'd found enough to be satisfied. Besides, we wanted to get to the next site before the temp. climbed up too high. We went back along the road for about two hundred yards and then stopped to take a picture of the river. Water in the desert is a wonder and after seeing these broad rock beds, I'll have to do some research about access points so I can do some crick walking of my own.

When I looked down from my vantage point along the road, I saw a rather large rock that had the white chalky veining indicative of agate. I picked it up and it had the weight to be heavy with agate. Being a bit hot and trying to not waste any time, I decided to just set it in the car and figure it out when we got home. More about this piece later, lol.

On to Morenci we went. Morenci is the home of one of the largest open pit copper mines in the US. The site we were looking for was located about 13 miles north of town along the Coronado trail. It took ten miles before we reached the end of the mine and its tailings! Most of it was very well fenced and all of it was posted. The kids and I amused ourselves by watching the occasional flashes of green rock in the tailings piles as we drove by. Only once did I see a piece of “Oh-my-goodness!” blue that was about a foot long and at least six inches thick that made me think longingly and guiltily of wire cutters, LOL!

This location along the mountain highway is known for it's obsidian. As we got near, we started to see black glassy seams in the cut. At approx. the right mileage, we found a wide turnout where we could park. The view of the valley below us was spectacular.


The guidebook had said that the turnout was actually made of rubble from the road cut and full of obsidian, but the mileage was a bit off. I think we were actually at an earlier turnout. Or maybe they had improved the road since it was written, I'm not sure. At the northern end we did find some nice fragments of obsidian in black and mahogany. The cut further up the road had a very visible dike of mostly black and grey striped obsidian. But for some reason I decided to look at the southern end of the wide turnout and hike down the hill a few feet. What I found was a dike of mahogany obsidian that was about 15-20 feet wide, running down the side of the hill. I walked about a hundred yards down the slope and still didn't run out of obsidian. It was awe-inspiring.

By this time the temp was in the low 90's, even though we'd climbed in elevation considerably. Again, about an hour was my limit and even then it was pushing it. By the time I climbed back up to the car, I was feeling a bit woozy and my face was bright red. I powered down some more water, but I still felt the effects throughout the rest of the day. I only collected about half a mop bucket of obsidian but it was very rewarding just to see all of it. This picture was taken dry and it's lovely stuff.

It was only about 12:30 but we were done. We drove back leisurely, enjoying the scenery and stopped for a wonderful lunch in Safford. When I got home, I started cleaning up my loot to get a good look at what we'd found. The last thing I tackled was the big rock and was almost blown away – there was a crystal lined cavity that had been completely filled with loose dirt at one end of it.

When I looked closely, I could see small dogtooth calcite nestled in among light blue quartz druse – and a few honking crystals that I think might be another form of calcite, but as I'm a lousy mineral person I could be wrong. It's a shape I'm not used to seeing calcite in, but that doesn't mean anything with calcite.

Laced throughout the rest of the piece is a golden brown mossy agate – at least on the top. In some areas I see light blue seaming, but I'm not prepared to bang on it to see if I find anything else in it.

I wasn't planning on having a cabinet specimen, but it looks like I have one anyway. Now I just have to figure out where to put it! What a great trip this was!