Donate now to keep mindat.org alive!Help mindat.org|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 Mindat
The most common minerals on earthMineral PhotographyThe Elements and their Minerals
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
StatisticsThe ElementsMember ListBooks & MagazinesMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Cold cases. Yellow orange unidentified on hydrotermalite.

Last Updated: 9th May 2016

By Giuliano Bettini

Reasons for health and old age, my "mineralogical trips" to the island of Elba and Leghorn Mountains have stopped.
Now I'm doing photos.
I'm reordering my old collection.
Here I am referring to the locality Nibbiaia, Rosignano Marittimo, Livorno Province, Tuscany, Italy.
http://www.mindat.org/loc-252520.html
Locality description:
Radiolarites & Hydrotermalites, about 800m east-south-east of Nibbiaia.
Mineral list: Anatase, Brookite, Quartz. Millerite, etc.


I was examining some samples of this area. Here in the past were mainly found Anatase.
Carefully examining etched samples (cold dilute HCl), interesting "unknown" are appearing.


------------------------------

In the very first time, examining a sample under the microscope, I saw this acicular crystal (Field of View: 1.5 mm).






Subsequently, in fact, I have noticed that this and other samples contain rare fragments of a yellow-orange material.
So I decided to make a sweep analysis of different specimens.
I have thus noted the presence of other crystals, and yellow-orange crusts and coatings here and there on the specimens.

I show some pictures.


Crystals.


FoV 1.5 mm.
FoV 1.5 mm.
FoV 1.8 mm.
FoV 2 mm.
FoV 1.5 mm.
FoV 1.5 mm.
FoV 1.8 mm.
FoV 2 mm.
FoV 1.5 mm.
FoV 1.5 mm.
FoV 1.8 mm.
FoV 2 mm.


FoV 1.5 mm.
FoV 1.5 mm.
FoV 2 mm.
FoV 2 mm.
FoV 1.5 mm.
FoV 1.5 mm.
FoV 2 mm.
FoV 2 mm.
FoV 1.5 mm.
FoV 1.5 mm.
FoV 2 mm.
FoV 2 mm.



Small masses, coatings (very rare). FoV 3 mm.




------------------------------

Is it the same mineral?
I suppose yes, even if sometime the crystals appear slightly more orange, and the crusts slightly more yellow.
Comparison:


FoV 3 mm.
FoV 1.5 mm.
FoV 3 mm.
FoV 1.5 mm.
FoV 3 mm.
FoV 1.5 mm.



Yellow orange unidentified is unidentified. So far.




Article has been viewed at least 2602 times.

Comments

Hi Giuliano!
Have you seen the colour of the streak? If it is yellow-orange, it could be crocoite! Is there any documentation about an occurrence of crocoite in that place? However... there is always a first time for everything!
Greetings from Lombardy by Riccardo.

Riccardo Modanesi
5th Apr 2016 10:04am

Dear Riccardo,
thanks for your comment.
No, I have no idea of the streak, too small to test.
In my extensive research on the Interne, me too I thought to Crocoite. No, it's never been found, even in Tuscany as far as I know.
We'll see.
Cheers,
Giuliano.

Giuliano Bettini
5th Apr 2016 10:30am
Crocoite would seem unlikely given the geological environment - cherts with hydrothermal quartz veins? For crocoite, you would need both lead and chromium sources. The lead could come in through the hydrothermal veins, but the chromium would need to be from maybe an ultramafic source.

Steve Sorrell
8th Apr 2016 10:00am
Hi Steve.
I agree that Crocoite would seem unlikely here, even because never found.
But as to the "ultramafic soils" (I'm not a geologist, I just gave a quick look to the Internet)
it seems ok, and Chromium seems to be present..

Example
http://link.springer.com/article/10.1007%2FBF02913340#page-1

Also quoted the "Livorno hills" (what I called "Leghorn mountains").
We are here.
Anyway, honestly IMO Crocoite would seem unlikely.
We'll see.
Many thanks for your comment.
Giuliano.

Giuliano Bettini
8th Apr 2016 5:08pm
Perhaps minium or litharge, both lead minerals.

Keith Wood
11th Apr 2016 11:41pm

In order to leave comments to this article, you must be registered
Mineral and/or Locality  
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 1993-2017, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: December 15, 2017 04:18:25
Go to top of page