Log InRegister
Quick Links : The Mindat ManualThe Rock H. Currier Digital LibraryMindat Newsletter [Free Download]
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat ArticlesThe ElementsThe Rock H. Currier Digital LibraryGeologic Time
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsClubs & OrganizationsMineral Shows & EventsThe Mindat DirectoryDevice SettingsThe Mineral Quiz
Photo SearchPhoto GalleriesSearch by ColorNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography

GeneralMineral Specimen Provenance

7th Nov 2015 16:35 UTCLarry Maltby Expert

00178590016016587232563.jpg
While doing some research prior to posting a photo that I took at the Denver Museum of Natural History in 1982, I came upon a photo of the same specimen submitted by Rock Courier in 2010.




The specimen on the left was photographed at the Denver Museum of Natural History in 1982. It is approximately 14.5 cm wide and 11.7 cm tall


The photo on the right was submitted by Rock courier on May 7th. 2010 with the following description: “Microcline var. amazonite and minor white Albite. Specimen was said to have come from the Reeser Claim. R. Kosnar specimen (1974). Scale at bottom of image is an inch with a rule at one cm.”


From the above information we can deduce the following provenance:


The specimen was collected in 1974 by Richard Kosnar.


It was acquired by the Denver Museum of Natural History and was residing there when it was photographed by Larry Maltby in 1982.


During a Museum renovation, it was likely offered for sale and acquired by Rock Courier. He submitted a photo of the specimen to Mindat in 2010.


Can anyone add to this story?

7th Nov 2015 18:03 UTCAlfredo Petrov Manager

Maybe I missed it, but I don't see Rock saying that he acquired this specimen himself. Rock used to photograph specimens in museums all over the world, and has uploaded many such photos to Mindat without owning the specimen himself.


Many of the photos of museum specimens that Rock has uploaded to Mindat were taken decades ago and were on kodak slides. In recent years Rock set about systematically digitizing his thousands of slides for upload to Mindat. So we really don't know when Rock took the photo - It could have been a very long time ago.

7th Nov 2015 21:41 UTCLarry Maltby Expert

I see your point Alfredo. When I saw Rock’s scale in the photo I thought that was a good indication that he owned the specimen at one time but, as you point out, he may have photographed the specimen before it went to the Denver museum.


I attributed the collecting of the specimen to Richard Kosner but that is also too strong of a statement. Richard Kosner was actively collecting at Lake George in the 70’s and many microcline specimens were recovered by him but Rock does not say that he collected this specific one. Perhaps Brian Kosner will see this and comment. I will check the Colorado issues of the Mineralogical Record for more information. It is a distinctive piece and it may have been written up. Also, someone may come forward and establish that the specimen is still at the Denver Museum.


The path that a mineral takes through the mineral collecting world is interesting to me but I can see that it requires a lot of research. In the future the minID will help with this.


Thanks for the help.

7th Nov 2015 22:43 UTCAlfredo Petrov Manager

Yes, Larry, I agree that minID will help.


Several important museums gave Rock permission to open the cases and put his 1-inch brass bar into the case for photography, so the specimen might have already been in the museum when Rock took the picture. Too late to ask him, unfortunately. A few days before he passed away, Rock was telling me stories of his travels to museums around North America and Europe to document the world's "best minerals", a topic which always fascinated him (as also evidenced by the encyclopaedic "Best Minerals" project that Rock started on Mindat). It was interesting to hear Rock talk about which museums both large and small rolled out the welcome mat for him, and which others refused to grant permission for photography. There was no correlation between the importance/size of a museum and whether or not they gave him permission. Some very important (and presumably busy) institutions were happy to assist Rock, and other less-well-known museums that could certainly have benefitted from the extra publicity refused to cooperate. I wish I'd written the list down, but my memory is terrible, and now it's too late to ask again :-(

8th Nov 2015 00:19 UTCFred E. Davis

Rock photographed many specimens in the Yale Peabody Museum of Natural History. I believe that was in the '70s (long before I started as a volunteer), and he provided copies of the 35mm slides to the museum (we still have them). To the best of my knowledge, these were specimens in the store room and not on display.

8th Nov 2015 01:26 UTCBob Harman

LARRY, ALFREDO and others. Speaking of specimen provenance, the very first picture that I posted on page 1 of the Midwest geode thread was an aragonite from Monroe County, Indiana. I had acquired it about 10 years ago and promptly when posted, STEPHEN ROSE, Mindat user, let it be known that he had self collected it some 50 years ago in 1965 while a student at Indiana University. Several years later he sold it to Indianapolis mineral dealer HARRY SERING. Where it went from there is unknown, but it turned up for sale at the Bloomington show about 2005 when it was acquired by a collector friend of mine who, for a small profit, promptly resold it to me. Just several months ago I donated it to the Indiana State Museum. They had it pictured, with attribution to me, in the recent Min Rec supplement as one of their specimens pictured in the state museum pages. It will shortly go on permanent display in the museum, when renovations are completed. CHEERS.......BOB

8th Nov 2015 04:59 UTCBart Cannon

04118650016016587248574.jpg
Rock's scale bar was marked at one inch, and one cm. I have attached a photo of one of my zektzerites which he photographed in 1979. The bar and markings are plainly visible. He returned copies of his 35 mm slides to the specimen owner. His photo technique was fast and effective. Black background and a flash. I think he used Ektachrome rather than Kodachrome since the latter had a shorter storage life His photos seemed a touch bluer than Kodachrome. Full information was neatly hand written in the slide's paper frame. That bar should be preserved somewhere. Maybe converted to a shirt pin and sold at an MR auction.


The best provenance begins with the field collector. I now try to provide a detailed description of the collecting history and ranking of each significant specimen I sell.

8th Nov 2015 14:15 UTCLarry Maltby Expert

Fred


It is interesting to know that Rock took so many photos in museums over the years. I also did that but I did not ask for access. I just photographed what was in the cases and now I have more work to do to digitize and prepare the photos for Mindat. My notes show that I took 17 photos at Yale in the 70’s most of them are of the dinosaurs. My kids were in awe of them! I have a lot of slides to work on but I am pushing 80 years old. I better hurry!


Bob


Great story of the “life” of a mineral. It is not often that the original collector reveals himself. This reminds me of that childhood story where a small wooden canoe falls into the head waters of a river and goes through many obstacles drifting down stream until it reaches the ocean.


Bart


Nice to hear from you. I remember that awhile back that you mentioned that your dad used to drive you down into the quarry at Clay Center. I also collected at Clay Center in the 60’s. I will try to digitize those pictures soon if I can find them. I even have a photo of a blast along the quarry wall. That is now a pretty rare photo. I wonder if someone will save the little scale that Rock used. It is an ikon of Mindat photography.

11th Nov 2015 15:13 UTCJamison K. Brizendine 🌟 Expert

I don't know if Jolyon caught this, but he recently uploaded a poster from the 1988 Denver Mineral Show. The specimen that was featured on that poster is the same one the Larry and Rock took.


12th Nov 2015 12:59 UTCLarry Maltby Expert

Jamison,


That is an interesting observation. It reveals another event in the “life” of this specimen. I think that if Jolyon or one of the other managers would add the minID to the photo of the poster that it would also be added to the record on the minID page.


Look here: http://www.mindat.org/38Y-3UN


I noticed that my photo has been added to this page even though I uploaded it in the “other” category rather than the “mineral” category. I did not use the “mineral” category because I did not have a depth dimension. The width and height that I show were calculated using Rock’s scale. I think that if all three photos are shown on the page it would illustrate the essence of what the minID page is all about.

12th Nov 2015 17:57 UTCRob Woodside 🌟 Manager

Thanks Larry and Jamison! I'm the guilty party for editing things without permission!;-)

12th Nov 2015 20:19 UTCLarry Maltby Expert

Rob,


No need to feel guilty! I would not expect that a manager would need permission to straighten out a minId number. I have some more interesting information on this specimen and the “white stripped” microcline specimens in general. I will post as soon as I have time to write it up.


Here is another specimen with two different minId numbers.

12th Nov 2015 23:38 UTCRob Woodside 🌟 Manager

Thanks Larry, from the colours alone you'd think they were different rocks! I look forward to your note as I've always wondered about these stripped amazonites.

13th Nov 2015 18:53 UTCLarry Maltby Expert

Additional research has provided more insight into the striped microclines. The Mineralogical Record supplement “Mineral Collections in Colorado” (November – December 2014) shows three specimens with interesting labels.


First, the specimen photographed by Maltby and Courier shown at the start of this thread, was also shown in the supplement. It was presented by the Denver Museum of Nature and Science. The label says that that it was acquired by exchange with Richard A. Kosner. It also says that the location for the specimen is Crystal Peak, Teller Co. Colorado which is in conflict with other labels for that specimen. Note: all of the Kosner and Coil claims are listed in Lake George, Park Co. Colorado and the names most associated with the discovery and collection of the white striped microclines is Kosner and Coil.


The Mineralogical Record credits Clarence Coil with the original discovery of the striped microclines. Here is a quote from the Biographical Archive: “Coil's best-known find was the pocket of large crystals of deep blue amazonite with a selective overgrowth of albite on some faces to give a "striped" effect to the crystals.”


Second, the next specimen is a superb striped microcline presented by the Kosner family. The label says that it came from the “striped pocket”, RAK Yucca Hill Claim, Park Co. Colorado and collected by Richard A. Kosner with Clarence Coil.


Third, is a specimen presented by David Roter. It is a classic striped microcline. The label says that it came from Lake George district, Teller Co. Colorado. When the same specimen was shown at the 2008 Tucson Show the label read Crystal Peak, Teller Co. Colorado. Due to the uniqueness of the striped microclines, unless new information is found, I would doubt that this specimen came from Teller Co. Colorado. This specimen, photographed by Jolyon at the 2008Tucson Show, is shown below. Enlarge the label to read the locality.





There are other specimens that are labeled “white cap” microclines. They have a white zoning that penetrates the crystal to a depth of several millimeters and are quite different from the “white striped” microclines. I took a lot of photos at shows and museums during the 70’s and 80’s and I think that I have more of these. When I find them I will post them here.


As you can see there are problems with the labeling. Personally, I think that all of the classic white striped microclines came from the Lake George area, Park Co. Colorado.

13th Nov 2015 19:53 UTCRob Woodside 🌟 Manager

Thanks Larry. I cleaned my caption edits and referenced this thread on Rock's photo.


Perhaps Lake George being in Park and Teller Counties is part of the confusion. But Crystal Peak is not Yucca Hill where RAK appears to have had several claims including the one possibly found by Coil http://www.mindat.org/loc-221086.html If that's the correct locality and the striped ones really are unique then these photos should be posted there.


You allude to white caps being different. Is this one?




I look forward to seeing more of your photos when you can post them.

14th Nov 2015 16:20 UTCLarry Maltby Expert

Yes Rob,


During this process I looked at all of the microclines shown on Mindat. The term “White Cap” was used by Rod Lavinsky and others several times when describing specimens like the one that you show. The term “white striped” seems to have been used exclusively for the high contrast specimens where the white looks like a thin coating almost as if it were painted on.


I think that you are right when you pointed out that the Lake George area is split by the county line between Park County and Teller County and that may cause some confusion with labeling. I placed the Mindat icon on the map of the Lake George locality on the topographical software that I have in my computer and found that the county line is only 2800 ft. to the east. It is possible that some of the Lake George diggings are across the line in Teller County. Also, Crystal Peak is 2.6 miles to the east, Florissant is 4 miles to the southeast and Piles Peak is 18.8 miles to the southeast.

15th Nov 2015 16:00 UTCRob Woodside 🌟 Manager

Thanks Larry. It is not just the two counties, but as you found, it is also the closeness of the localities. As I recall the striped microclines were somewhat greener than other amazonites. Is there a single striped locality? The different looking "white caps" are from the same ranch. http://www.mindat.org/loc-156650.html How unique were these?

17th Nov 2015 14:11 UTCLarry Maltby Expert

07014180016016587246202.jpg
The photos below show a collection of “striped” microcline with smoky quartz specimens from a mining claim named the Smoky Hawk Mine, Crystal Peak, Teller Co. Colorado. The location label is given by the original collectors, Joseph Scott and Tim Doris and clearly shows that the “striped” microclines were found in Teller Co. in addition to Park Co. The display was presented at the Denver Gem and Mineral Show in2008. Mindat has a location page for the Smoky Hawk claim, Teller Co. showing 41 specimens including high quality microclines and some very good fluorites.

00059100015652229656142.jpg
Microcline with smoky quartz, Denver Show, 2008
00059100015652229656142.jpg
Microcline with smoky quartz, Denver Show, 2008
01602880014947178674493.jpg
Microcline with smoky quartz, Denver Show, 2008

17th Nov 2015 14:18 UTCLarry Maltby Expert

07217920016016587259928.jpg
The Denver Museum of Natural History presented a case of Colorado Minerals at the 2008 Denver show that featured the “striped” microcline that was shown on the poster for that year. (See Jolyon’s photo above) The specimen can be seen here in the upper right corner.


17th Nov 2015 14:46 UTCOlav Revheim Manager

Thank you all for this interesting thread!


I have a couple of questions regarding the white-cap amazonites. Is the white color just a faded amazonite? If so, are there any indication of high temperature hydrothermal fluids in this system?


I am asking because an old article observes that the amazonite color fades at temperatures higher than 250 deg C, and that temperatures around 300 deg causes the color to disappear rather quickly. ( see Oftedal (1957): http://www.minersoc.org/pages/Archive-MM/Volume_31/31-236-417.pdf ) I wondered if the same mechanisms were at play for the whitecap amazonite.


Olav

18th Nov 2015 17:19 UTCLarry Maltby Expert

Hi Olav,


Yes, there are several professional papers that discuss hydrothermal activity in the Pikes Peak batholith. I have included two below that are fast reads.


https://gsa.confex.com/gsa/2015AM/webprogram/Paper270037.html


http://www.coloscisoc.org/news/2012/Dec2012CSSNewsX.pdf


I have also given another two references that propose the green-blue coloration of amazonite in due to the presence of lead as an impurity and the change from green-blue to white is due to the depletion of lead during crystallization. I doubt that this is the end of the story.


http://www.minsocam.org/ammin/AM70/AM70_794.pdf


http://proctorfamilytrustcollection.com/PDFs/NGS.MicroclineFeldvarAmazonite.p81_82.pdf


Thanks for the reference that you gave. I have added it to my files.

18th Nov 2015 20:20 UTCOlav Revheim Manager

02076710015654957243732.jpg
Hi Larry,


Thank you very much! It seems like also these amazonites fade at temperature as they do from other places. The reason I asked are these:




Here late hydrothermal activity has brecciated parts of the pegmatite, and some of the amazonite have changed color to red, presumably due to high temperature hydrothermal fluids.


I have some additional papers for your archive, two of them relating to the locality of the photographed amazonite, and another on color.


http://www.minsocam.org/ammin/AM78/AM78_500.pdf

http://foreninger.uio.no/ngf/ngt/pdfs/NGT_63_4_199-209.pdf

http://foreninger.uio.no/ngf/ngt/pdfs/NGT_40_2_133-156.pdf




PS. Sorry to hi-jack the tread on provenance of the very special specimen in your first post.


Olav

18th Nov 2015 23:10 UTCRob Woodside 🌟 Manager

No hijacking, just good food for thought. Thanks!


So are the white stripes albite and the white caps microcline?

20th Nov 2015 11:13 UTCLarry Maltby Expert

Olav,


Great photo of the effects of hydrothermal alteration of an amazonite crystal. We can even see areas of dissolution and penetration of the fluids along what appears to be lines of the crystal lattice. The color change is very mottled as you would expect. Some of the specimens labeled “white cap” from Colorado are mottled suggesting alteration but others are very sharp suggesting some other mechanism like the depletion of Pb during the final stage of crystallization. It would be nice if we could see if the interior of the Colorado specimens were also mottled similar to what your specimen shows. Broken pieces of crystals are probably encountered during excavation but specimen collectors don’t save them unless they can be used in a reconstruction project. Without being able to observe the opening of a pocket and its contents first hand, I think that we are stuck with speculation.


Rob,


I think that the “white caps” are probably microcline but I am not sure about the “striped” specimens. In spite of a lot of searching, I cannot find a reference to an analysis that would prove that the stripes are selectively deposited albite. It is very possibly albite but it could also be a secondary deposit of white microcline.


An interesting feature about the geology of the Pikes Peak batholith is that the late stage pluton near Lake George is composed of a core of sodic rocks surrounded by a ring of potassic rocks. Near the contact of these two rock types would be plenty of K to make microcline and also plenty of Na to make albite. The fact that cleavelandite is found on some of the specimens from this area supports the choice of albite. I just wish that I could have found an analysis that proves it.


Here is the reference on the Pikes Peak Batholith.


http://digitalcommons.trinity.edu/cgi/viewcontent.cgi?article=1002&context=geo_faculty

20th Nov 2015 15:36 UTCRob Woodside 🌟 Manager

Thanks Larry. If somebody has a striped piece, wouldn't Raman sort albite and microcline in about 10 seconds?

5th Dec 2015 14:58 UTCLarry Maltby Expert

07633260016016587268123.jpg
Here is some additional historical provenance regarding amazonite and smoky quartz from the Crystal Peak area in Colorado.


This display at the 1982 Colorado Springs Gem and Mineral Show is of a large pocket discovered in 1981 near Crystal Peak, Colorado. Large plates of crystals were recovered and donated by Jerry and Thelma Hurianek and Barbara and John Slagel to the Denver Museum of Natural History for pocket reconstruction.

08991180015652229656318.jpg
Amazonite and smoky quartz pocket

Crystal Peak, Teller County, Colorado, USA
08991180015652229656318.jpg
Amazonite and smoky quartz pocket

Crystal Peak, Teller County, Colorado, USA
05753230014947178927646.jpg
Amazonite and smoky quartz pocket

Crystal Peak, Teller County, Colorado, USA


00782620014947178936949.jpg
Amazonite and smoky quartz
03969180014947178939141.jpg
Amazonite and smoky quartz
07955350014947178936992.jpg
Amazonite and smoky quartz
00782620014947178936949.jpg
Amazonite and smoky quartz
03969180014947178939141.jpg
Amazonite and smoky quartz
07955350014947178936992.jpg
Amazonite and smoky quartz
00782620014947178936949.jpg
Amazonite and smoky quartz
03969180014947178939141.jpg
Amazonite and smoky quartz
07955350014947178936992.jpg
Amazonite and smoky quartz

5th Dec 2015 16:18 UTCD. Peck

Larry, Thank you for posting those photos. They are the kind of thing that most of us never get to see.

5th Dec 2015 17:41 UTCBill Dameron 🌟 Expert

I collected an amazonite with a white cap and stripes from a small, one off pocket in the large area known as Crystal Peak, in Teller County, in 1998 in the company of (and the dig discovered by) well-known Colorado collectors Larry and Carmen Piekenbrock. Not a great specimen but decent. White stripes and caps occur in many small digs in the area (small meaning holes dug about one or two meters into the peg before they seem exhausted).

6th Dec 2015 11:35 UTCLarry Maltby Expert

Hi Don,


As you probably remember, there were a lot of North American minerals still being produced in the 60’s, 70’s, and 80’s. During that time I was very active in attending shows and visiting museums. I took a lot of photos of minerals that eventually went into private collections and are no longer on public view. I am in the process of preparing many of them for posting on Mindat. This gives me the chance to relive the “good old days”.


Bill,


We would like to see a photo of your specimen. If you get around to photographing it, please post it here. Also, include photos of digging a pocket if you have them. The selective coloration of a “stripper” remains a mineralogical mystery.

6th Dec 2015 17:04 UTCSteve Maslansky 🌟

The "white caps" from the Lake George region has been identified as microcline by both XRD and Raman. Joe Dorris and I have done further trace element analysis on various shades of blue and greens, as well as the host rocks. We hope to publish some of this data in the future.

6th Dec 2015 19:02 UTCRob Woodside 🌟 Manager

Thanks Steve. The "white caps" are microcline, but what are the stripes? Albite as reported?

7th Dec 2015 17:34 UTCSteve Maslansky 🌟

Rob-The material we looked at, "caps" and "stripes" from the Smoky Hawk Trend were at least all K-spars. Mostly microcline, although some peaks suggested possibly orthoclase. I know in the past similar material from the area was reported as albite.

9th Dec 2015 20:00 UTCJ. Schmitt

New to posting a question: Thank you for any replies



I have a very nice White Cap from Crystal Creek, with a 1/2 top white cap termination and 2 stripes down the side of the crystal, with 1 stripe encompassing 1/3 of the crystal. I have been trying to learn if the "core" of these crystals, as seen from the bottom, all exhibit the "white core" I find with mine. 80% of the core is all white.

9th Dec 2015 20:12 UTCStephen Rose Expert

Larry,


Your reference to the "childhood story" certainly is to the classic books by Holling C. Holling. In this particular case, "Paddle to the Sea." Some of my favorites as a child as well. Great thread. It was wonderful to see the photo of the aragonite to which Bob Harmon refers after so many years.


Steve

9th Dec 2015 21:13 UTCRob Woodside 🌟 Manager

Welcome to Mindat, J. Schmitt. That is an interesting question. Most people who have an unbroken capped or striped xl would be horrified at the thought of finding out how deep the white stripes go. Do you have any pictures of a broken xl showing the penetration of the stripes?


Thanks Steve. I added a note to the smoky Hawk amazonites. How did you analyse them?

9th Dec 2015 22:21 UTCSteve Maslansky 🌟

09023250016016587277794.jpg
Rob-


Analyses have been done by XRF, XRD and/or Raman. The "cores" of the amazonites vary greatly with no common microcline to almost all common microcline. Here are couple of pictures showing cores and amazonite "roots". All are Smoky Hawk materials.

05846520015659719132750.jpg

07308590015659719138189.jpg

10th Dec 2015 01:06 UTCRob Woodside 🌟 Manager

Thanks so much Steve. They are very interesting. Could you please post them here under the Smoky Hawk locality?

11th Dec 2015 20:26 UTCLarry Maltby Expert

That's it, Steve Rose,


"Paddle to the Sea", I forgot the name. I doubt that many kids are reading that story now unless someone makes a video game version of it.

11th Dec 2015 20:57 UTCLarry Maltby Expert

01135090016016587283733.jpg
Steve Maslansky,


Thanks for the interesting photos showing the “roots” of the green/blue Microcline crystals. It appears that the color is associated with the pocket crystallization but not the crystallization of the host granite. That is more food for thought. Perhaps your data on the green/blue color will shed some light on that. We will be looking forward to the publishing of the data.


I have posted the photo of another “striper” that was collected prior to 1975. The label only states that this specimen is from Colorado, however, the stripes are identical to specimens found in the Lake George area of Park County. The specimen was displayed by Mr. and Mrs. Armstrong of the well- known Armstrong floor covering company. It was displayed at the 1976 Greater Detroit Gem and Mineral Show. It is a medium sized cabinet specimen.


20th May 2016 03:48 UTCBrian Kosnar 🌟 Expert

01325630016016587291926.jpg
Hi Everybody,


I wanted to weigh in quickly to clear up any confusion. My Dad collected the specimen in question with his partner Clarence Coil in the early 1970s. My Dad and Rock Currier were great friends since the early 1960s and Rock would often visit my Dad to photograph the collection. These photographing sessions took place every few years for the better part of a fifteen year span. Rock never owned the Amazonite above, it was only in my Dad's collection and then traded/sold to the Denver Museum of Natural History (now the Denver Museum of Nature and Science).


If anybody has any other questions about this thread, please feel free to contact me.


Coincidentally, the large Sweet Home Mine Rhodochrosite in the DMNS case photo from 2008 also came from my Dad. He collected it with my grandfather (my mother's father) in 1978 and also sold it to the Denver Museum shortly thereafter.


Here's a photo of me holding the piece in one of the back rooms of the Denver Museum in January of 2010


20th May 2016 04:02 UTCBrian Kosnar 🌟 Expert

Just one more thing, I wanted to mention that the "striped" and "white cap" Amazonite specimens are not unique to one pocket, district, or even county in the Pike's Peak Batholith. I personally have collected both "striped and "white cap" Amazonite crystals near the base of Mount Evans, which is easily 50 miles away from Pike's Peak as the crow flies.


Additionally, year ago Gene Foord at the USGS analyzed several of the "striped" and "white cap" Amazonites from my Dad, and it turned out that the selective deposition on the crystals was either Anorthite or Albite.

20th May 2016 04:14 UTCRalph S Bottrill 🌟 Manager

Microclines commonly exsolve albite or oligoclase on cooling, forming microscopic to macroscopic white veinlets and commonly thin crusts; anorthite would be pretty odd but not impossible.
 
Mineral and/or Locality  
Mindat Discussions Facebook Logo Instagram Logo Discord Logo
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2024, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: March 29, 2024 00:25:59
Go to top of page