FMF - Friends of Minerals Forum, discussion and message board

[Philip Simmons]

Hi all,

Sorry for the long wait between postings. I have been out field collecting almost non-stop for the past 6-8 weeks as it is prime season for outdoor activities. I will post some of our recent findings soon as I get the minerals cleaned and prepped. For now I want to present the Cookes Peak District, which has produced many great fluorites along with other interesting minerals.

The Cookes Peak and Jose Districts were first discovered in 1876, and production started in 1880. The first target was argentiferous galena, followed by oxidized lead and zinc ores. Final production was focused on the primary lead and zinc sulfides. The mines ran intermittently through 1953. The ore bodies are classified as manto-replacement type, and were usually on the order of less than 1,000 tons per zone. Overall production of the District was relatively small: 7.7 million tons of lead, 5.8 million tons of zinc and >6,000 ounces of silver. However, it's mostly the gangue minerals (fluorite, vanadinite, sidwillite, calcite, quartz) that are of interest to collectors.

[Philip Simmons]

Some more photos from the Cookes Peak District.

[Philip Simmons]

We worked the pocket for 10 days and had dug all the fluorite in sight. Everybody was ready to go home and recover after spending so much time in the dingy, dirty mine. A few days later I called Chris, Mike and Fred to see if they wanted to dig in the pocket area a little bit more. Both thought there was still some potential to find good specimens, but Mike and Fred had other commitments, so it was just Chris and I collecting this time.

We dug in a promising area that had produced some highly etched green fragments of fluorite, and within a couple hours we opened up another chamber to the large pocket. Interestingly enough, this part of the pocket was under muck in the old drift the miners had driven well over a hundred years ago. This time the pocket produced vibrant ("jolly-rancher") green etched octahedrons sitting on 1st generation etched blue cubes. This 4 day trip produced many more specimens, including a large plate of green and purple fluorite, known as the "Jolly Green Giant". This specimen also now resides in the NMBGMR Mineral Museum collection.

[Philip Simmons]

The Cookes Peak District also produces some other great specimens besides the fluorites form the Surprise #1 workings. I've put together a nice representation of the not so well known specimens from this area.

[Philip Simmons]

More Cookes Peak area minerals.

[Tobi]

Thank you so much, Philip, browsing this is a pleasure!

[Philippe Durand]

thank you for sharing this field report.
a dream for only money pick collectors

[Philip Simmons]

Wow! It's been a whole year since I last posted any New Mexico adventures. Time really does fly. Much has happened in the past year, and I have had the pleasure of finding some good specimens. However, I will start off with collecting adventures from the past, including some of my most exciting finds in over 30 years of field collecting.

I am going to talk about collecting in the Carlsbad Potash District in the SE corner of New Mexico.

[Philip Simmons]

All of the History, Production and Geology comes from the article I wrote for the Mineralogical Record in January/February 2013.

The Carlsbad Potash District was first located in 1925 about 35 kilometers east of Carlsbad when an oil/gas well intercepted beds of a soluble reddish mineral. Analysis was performed on the mineral, and it was discovered to be almost pure sylvite (potash). More exploratory drilling revealed the presence of extensive beds of potash, and by 1930 the first shaft was sunk (U.S. Potash Mine) to develop the ore bodies. A boundary known as the KPLA (Known Potash Lease Area) was set aside in 1934 specifically for mining the important commodity used in fertilizer. More mines were soon developed, and by the early 1940's, eight large mines were operating in the District. The Kerr McGee mine, where spectacular blue halite is found, was first opened in 1965.

Mining peaked in the 1960's when typical yearly production amounted to more than 23 million ore tons. The Carlsbad District was the world's leading producer of potash from the 1930's through the 1960's. Production slowed by the 1970's and huge mines in Canada and Russia were opened that dwarfed production from Carlsbad. However, companies still managed to mine the extensive ore bodies and production is still ongoing today. Two major mines are currently operating in the District. Overall, the Potash District has produced greater than 900 million tons of ore and driven more than 16,000 kilometers of tunnel.

[Philip Simmons]

I started working in the District as a mining engineering intern in the summer of 2007. My boss, the Chief Mine Engineer (Tom), had a few cleavage fragments of dark blue halite in his office from the underground workings which piqued my interest. I had not really expected to do much collecting in the mines because of the evaporitic nature of the deposits, and seeing beautiful halite was quite the surprise, even if it wasn't complete crystals. I eventually convinced Tom to take me to the area that produced the wonderfully colored halite, and the resulting trip was one of the most memorable experiences of my life.

When I graduated from college in 2008, I was offered a position by the mining company as a planning and ore control engineer, and I accepted the position without hesitation. The mining company was fine with me collecting on my own time, and I spent many weekends exploring the blue halite zone, and came up with many great specimens and memories. Unfortunately collecting was halted in 2014 as the area became inaccessible through the ever present converging ceiling (known as the "back" in mining terms). The mines are relatively deep (500 meters) and all openings are slowly squeezing shut due to the soft nature of the rock.

[Pierre Joubert]

Thank you Philip. Fascinating stuff!

[Philip Simmons]

Now that I'm back from a great trip to Dallas to give a presentation and visit with many friends, I will continue to post about the Carlsbad Potash District.

[Chris Rayburn]

Philip, you may be coming to this, but what is the current thinking on the source of the color in these specimens? The explanation I've heard most often is radiation from trace isotopes in the halite, but I also understood that this was not yet definitive, at least as of several years ago.

[Philip Simmons]

Chris, I'm glad you asked! Tonight I am planning on posting pictures of the crystals we found, and then I will cover the topic of coloration in the halite. It is a very fascinating process, and we now understand in greater detail what causes the color compared to even a few years ago.

[Chris Rayburn]

Always happy to tee 'em up...and I'm not even a golfer.