Rockin the Rockies

Rockin the Rockies
Stowe Mtn

Sunday, October 12, 2014

Another Pocket of Crystals at Lake George CO

As I'm writing this I have a pocket of crystals waiting on me up at Lake George. The site is fairly remote, so I'm not too worried about losing it to another prospector. The crystals are also not great so far, so the crystals can wait a day or two.
Clay covered pocket material

Handwashed amazonite...acid next!
 We were in an unprospected area, at least not dug in several years, so I thought Bob and I might have a chance of finding something good. White quartz was dribbling down the hill in various places, so I chose one area and followed the quartz up the hill. As I followed the quartz up the hill I picked up a broken crystal or two so I knew there was pegmatite producing crystals somewhere above me. As I climbed the hill the float or surface quartz diminished to almost nothing, so I started to take a real close look at the surrounding rock. One rock in particular caught my attention. The rock was firmly fixed in the ground (not roll down) and it had a lot of surface crystallization sometimes called "rice rock" due to the small formed crystals in the host rock appearing no bigger that grains of rice. I split this rock with me pick axe and pulled it out of the ground. I noted a few quartz shards underneath the rock, so I figured the host pegmatite was nearby if not directly underneath me, so I commenced digging. Right away I hit Zindwaldite.
Scraper pointing to plate of  Zindwaldite with amazonite beneath, note purplish color of pocket clay 
Now zindwaldite is not an accepted mineral term these days so lets just call it mica and move on. Mica is a sign of mineralization, so I continued digging. Soon I hit a piece of pegmatite that had quartz, cleavelandite and microcline. Using the spit field test method I noted the microcline was in reality amazonite though pale. I set my pick axe aside and moved to my rockhammer and scratcher. No sense in busting up crystals with my pick axe. I moved slowly at first, but determined everything I was finding was float and in fairly bad shape (cleaved) so I got more aggressive with my rock hammer til I hit better material. Soon I dug into some purplish clay and the number of crystal pieces increased so I assumed I was finally in the pocket.
Purple clay/dirt identifies pocket
Still the material was not of great quality. All the smokys were damaged and while the amazonites were okay they were only pale blue/green color. Expanding the dig I discovered a large area of mica. I decided to spend some time carefully taking out the fragile mica to see if I could salvage a piece for a geologist friend of mine, he seems somewhat concerned (from a scientific perspective) that I rifle through the mica without caring to save any.
Chunk of Zinwaldite/Mica
After I got the majority of the mica out I noted a fairly large number of well formed amazonite crystals behind the spot where the mica had formed. My theory is that the mica was a late-comer to the pocket and formed in the open areas of the pocket where space permitted. Perhaps wherever the mica formed in the pocket is an indicator of excess pocket room and a large enough void for better/larger amazonite crystals to form. So I guess my theory for this pocket is that mica means a large void, which means bigger and better crystals... time will tell. As it was getting time to go home I asked Bob to keep digging out the pocket while I wrapped what I had.
Bob found a nice crystal and let me know there was a lot of mica/
zindwaldite still deep in the pocket, so if my theory is right there should be a lot more crystals down there. Stay tuned for next weeks addendum to this report.

Second Vist: I returned to the pocket and dug it out. There were some new ice crystals, but they are tough to save this time of year ;-)
Little bit of snow today
I found a few well-formed amazonite specimens to add to my collection though the quartz crystals I found were very disappointing. I continued the dig until I was over 5 feet down and about 6 feet into the hillside.
Nearly 6 Feet down and done... time to fill it in
 In order to continue I would have to take nearly 6 feet of overburden down, or 6x4x2 feet of dirt and rock down and shovel it out to continue forward. One cubic yard of dirt weighs about 1ton. I’ve never had much luck with purplish sparkly mud that happened to envelop this particular pocket. I believe the purple indicates an infusion of manganese which has correlated to poor quality specimens for me in the past. I decided to discontinue the dig as the effort was not worth the prize as the pocket had narrowed down considerably from its original size of about 1ft high by 4ft across to about 6inches high by 10inches across. Maybe somebody in a few years will stumble across the dig and want to put the work into it and get a few crystals… not me.
Couple specimens in the back of the pocket for somebody else
So it’s time to find another pocket before the snow flies. Hopefully the next one will have better material.
I pulled out about 90 collectible specimens. Upon hand-washing some of the crystals I noted some fluorite clinging to the sides of the amazonite, so hopefully the crystals will clean up better and prove more interesting than first blush.
Cleaning is done: below are some of the amazonite crystals cleaned (best I can do). I tried a couple acids and a little bead blasting but you can only do so much. The amazonite were etched considerably by the fluorite in the pocket. The fluorite filled in some of the etched holes on the amazonite which makes the amazonite look dirty as well.
Largest amazonite here is about fist-size

Saturday, October 4, 2014

Clear Quartz from the Idarado Mine

Is it still rock hounding if you enter a store and fine a nice specimen from a mine that is closed and will never reopen again and purchase that specimen, or is that just adding to your collection? If you don't want to read about crystals from the Idarado Mine, read no further.
Mt Uncompaghre from near an Idarado Mine Shaft
The fall colors this year in SW Colorado were spectacular. Everywhere I turned there seemed to be professional photographers. I stopped at one of the openings to the Idarado Mine to take some fall foliage pictures. When I got into the town of Silverton CO I noted a number of well formed quartz crystal plates for sale. Inquiring of the owner, she said she had purchased them from an elderly gentlemen as he needed money to supplement his meager retirement income. When I asked the sales lady where crystals came from she said the Black Bear Vein of the Idarado Mine... well, that cinched it, I needed a plate. The sales lady wouldn't budge on price, and even wanted to jack-up the price of the specimen I had picked out. Finally I asked to see the owner and quickly had a rapport with her since she knew what I was talking about when examining the crystals. I had my eye on two specimens, but when negotiations with the owner broke down, I bypassed the plate with a 5" double terminated crystal and opted for the 8" crystal grouping below. I preferred the aesthetic appeal of the structure of the one pictured more than the plate with the large double terminated single crystal. As the owner wrapped my specimen she made me feel even better about my purchase when she mentioned just last week she had to mail a similar, but larger $7500 specimen to a buyer in Texas. I don't have that kind of money to spend on crystals, but a dropping a Grant or two on a nice crystal or two throughout the year is doable.
8" Quartz Crystal Plate from the Black Bear Vein of the Idarado Mine

The Idarado opened up many mines in Red Mountain District and made them successful again. In the1880’s there was a mining boom on Red Mountain Pass. The Yankee Girl Mine was the most famous. This early mining boom was mostly over by the mid 1890’s. Later, in 1943, the Idarado mine leased its property to the US Government to reopen the Black Bear mine through the Treasury Tunnel. The tunnel went for 5 miles from the top of Red Mountain Pass though the mountains, to Telluride. The Idarado mined minerals for World War II. Minerals from the mine were made into metal for making planes, ships and tanks.
Mine2.JPG

The mine, present day
Picture by Ty Edder
In 1945 the Treasury Mill was rebuilt to mill lead, zinc, and copper ore. In 1946, a new crusher was installed at Idarado to increase ore production. By 1947, the Treasury Tunnel to Telluride was complete. In 1954, a big fire burned the Idarado buildings and they were rebuilt. By 1956, a new mill was built near Telluride. Red Mountain mill was shutdown. Idarado kept mines in Ouray going.
by Ty Edder 

For more information on the Idarado Mine see: http://ourayhistory.wikidot.com/idarado-mine

https://nmgs.nmt.edu/publications/guidebooks/downloads/19/19_p0130_p0140.pdf

Amethyst/Quartz at Creede, CO

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Well, now that I've got your attention the specimen above came from Brazil, but there is amethyst in Colorado, just not the big geode chunks exhibited at most rock shops. I have run across an occasional pale amethyst quartz crystal while rock hounding at Lake George, CO; however, personally I have never run across anything much bigger than a 1/2" crystal. I've also found what we in Colorado call onegite. Onegite is quartz with goethite inclusions which give it a sometimes purple appearance or amethystine look. I've also heard of geodes found in Colorado with pale amethyst enclosed, but have not pursued those. This past week I took a color tour of SW Colorado and recalled our Rock Club had a guest lecturer who owned a mine near Creede, CO that has amethyst. 
Colorado fall eye candy
After seeing a brochure advertising this claim the "Last Chance" I decided to check it out. Amethyst is associated with galena, sphalerite and chalcopyrite in an amethyst vein in the Creede district, on West Willow Creek.
 The  specimens consist of small pale pinkish-purple crystals interlayed with milky quartz and often in banded form called "sowbelly agate". There are also pockets of euhedral crystals, but they are few and far between. According to the owner of the Last Chance, only 2 pockets of crystals have ever been found in his mine going back to the first find in 1923. Creede was initially established as a silver mining town, with a very rich mining history, but you can google that information for yourself.
I called Jack the owner prior to setting out and he advised not arriving until noon as there was still some snow and ice on the dirt roads leading to his claim.
Self portrait of Jack in wood carving
Jack was not really open for business this last day of Sept, but he was eager to show me around and open his museum. I had planned to do a little rockhounding on the piles of  rock downhill from his mine, but thought better of that due to the snow and ice. I had my wife along and when she heard Jack had some amethyst jewelry for sale I knew she would buy something. I also thought I might be able to get Jack to throw in a bit of amethyst rough. After some negotiating we finally arrived at a price for a ring with some sowbelly agate rough thrown in. Jack selected a couple pieces he had sitting near his work-site and was quick to point out the specks of silver included in the specimens. While I didn't exactly get to rockhound this day, I met Jack a memorable personality, I got some amethyst rough I can work on, and my wife was happy with an amethyst ring.
10" slab of sowbelly agate (specks are silver inclusions)
1.5" Amethyst pendant created by me!

A couple days later on the way home from our trip we stopped at an out of the way rock shop. The owner had some amethyst crystals covered in calcite which did not appear to be gemmy.  She was selling the crystals for $4 lb, so I bought a couple and will see what they turn out to be
One of the Amethyst crystals with calcite removed... not gemmy, but a nice lusterous 2.5 inch crystal
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Another rock shop specimen, terminated but oddly zoned like a piece of  sowbelly agate,