Help|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on MindatThe Mindat Store
Minerals by PropertiesMinerals by ChemistryRandom MineralSearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
StatisticsThe ElementsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery


Posted by Rock Currier  
Daniel J. Evanich January 13, 2012 05:46PM
Here is an interesting old collection Butte, Montana, specimen of acanthite after polybasite (with malachite coating) that was analyzed in 2011 by John Attard and confirmed as such.

About three years prior, I purchased a box of five or six "ore" specimens from Butte, and noticed a few that were off-color from the usual black and brass sulphides seen from this classic American locality. One had a green coating along with a handwritten label calling out polybasite and its formula. I've read about similar examples from The Anselmo Mine and Star West Mine in Butte, but not actually seen one. The specimen is about 5cm in width with individual crystals in the 1.0-1.5cm size coated with green malachite (analyzed).

Does anyone have any comment on the specific mine occurences of acanthite/polybasite from Butte, Montana?

Edited 1 time(s). Last edit at 01/13/2012 09:12PM by Rock Currier.
open | download - Acanthite after Polybasite with Malachite--Butte Montana004_edited.JPG (273.2 KB)
open | download - Acanthite after Polybasite with Malachite--Butte Montana001_edited.JPG (281.4 KB)
open | download - Acanthite, USA, Butte @ polybasite1 copy.jpg (145.7 KB)
Rock Currier January 13, 2012 09:01PM
Thanks for your picture of the acanthite after polybasite. I think a more appropriate place to post it would be in one of the other forums of the message board rather than best minerals. At any rate before we could consider using it in best minerals the images would have to be uploaded to the Mindat database rather than just an attachment to a message board post. If you would like to do this I can help you there. You might also wish to consider running it through Photoshop or a similar program to improve the quality of the image. See the example in your post that I took the liberty of editing a little and including in the body of your post. I think that the specimen might be better placed in the Best Minerals pseudomorph A to C article.

Rock Currier
Crystals not pistols.

Edited 1 time(s). Last edit at 01/13/2012 09:13PM by Rock Currier.
Daniel J. Evanich January 14, 2012 03:33AM
Thanks, Rock. Appreciate the advise. I did post higher res images to the regular Mindat site under acanthite just after this post. See you in Tucson for the BAM dinner on either Thursday, the 9th, or Friday the 10th, yet to be determined. Once again, NO LOUD MARIACHIS allowed.........
Sorry, only registered users may post in this forum.

Click here to login

Mineral and/or Locality is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © and the Hudson Institute of Mineralogy 1993-2017, except where stated. relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: July 21, 2017 17:48:09
Go to top of page