LIVE REPORT! Gold and Silver Deposits in Colorado Symposium 2017 - last updated 16 minutes ago. Click here to watch.
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

Unknowns from Cornwall

Posted by Alan Barnes (2)  
Alan Barnes (2) June 24, 2012 09:15PM
I have a large cabinet sized specimen of uraninite from St. Terras Mine in Cornwall. Sat on the quartz matrix are two blue, presumably copper, minerals. Do any of you Cornish experts know what these two minerals are? One is a pale blue whilst the other is a much darker blue. There are no crystals because I broke a huge specimen in two and the blue patches were found in between the tightly packed quartz crystals. The very small amount of these minerals on the specimen has prevented me from being able to do a streak test so unfortunately I can't offer anything scientific that might help people identify the minerals........but if anybody has any ideas I'd be glad to hear them

Best wishes,
open | download - cornish unknown 1.JPG (194.4 KB)
open | download - cornish unknown 2.JPG (132.5 KB)
Jolyon & Katya Ralph June 24, 2012 09:28PM
Welcome to the world of the Blue/Green Grotties. Could be malachite, chrysocolla, connellite, botallacite, atacamite, paratacamite, brochantite or one of a dozen others. Unlikely to be able to identify it much further without some chemical work (eg dissolving in acid)
Rowan Lytle June 24, 2012 10:16PM
Maybe a uranium secondary, being with uraninite?

-Rowan Lytle

Food, Water, Shelter, Fire, Minerals.
Amanda Hawkins July 01, 2012 08:32PM

Steve Rust July 01, 2012 09:09PM
I love these green grotty things you never know what thy might be,
I would guess at something like Brochantite/Malachite on Native Copper for the 1st photo
The 2nd photo could be Malachite, it can be very pale green, or my be completely some thing else.

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 24, 2017 01:46:06
Go to top of page