FMF - Friends of Minerals Forum, discussion and message board

[supertxango]

Hi Jordi and Nurbo.

About the specimen of the Precaución Mine. The crystals that you have shown in the pictures is for sure calcite. Hemimorphite is so common and the 99% of the specimens have on it, but is really strange to find big crystals. If you see your specimen with magnifying glasses you will find the hemimorphite.

The hemimorphite crystals habit is some similar than the Ojuela Mine specimens but sadly much less smaller in size :-(

At the following links you will find hemimorphite pictures from Precaución Mine in the Spanish FMF Gallery:

https://www.mineralogia.es/index.php?level=picture&id=29942
https://www.mineralogia.es/index.php?level=picture&id=29379
https://www.mineralogia.es/index.php?level=picture&id=29721
https://www.mineralogia.es/index.php?level=picture&id=30065

[nurbo]

Hi Jordi, Juan,
So I looked the specimen over really carefully and the only crystals on it are similar in habit to the ones in the photo, there are no stacked or single tabular crystals, nor anything else that looks like regular Hemimorphite crystals of the type shown in the links anywhere on this piece, Im currently out of HCl but the shops open again today so I will go buy some and test it. Funny thing is it has 4 labels with it and all say Hemimorphite! none mention Calcite

Today I thought Id post some less showy pieces, first up is a very old Quartz point covered in a crust of Hemimorphite from a fairly unusual locality in Cornwall, then a Quartz sample with a small area of Eisenkiesel from the Sykes Mine, the latter is a rare find indeed. Sykes was only ever worked for copper, I didnt know there was any Haematite up there, Ive certainly never seen any, there obviously is on the West side where this piece was recovered but it is very unusual.

[nurbo]

The label's on the "Hemimorphite" were wrong, as always Jordi spotted it instantly, thank's jordi, I can now make it's 5th label, but it will at last be correct.. We broke a couple of minor crystal's off and dumped them in HCl and they immediately fizzed like crazy. I think it's safe to assume the locality is correct though. iI've added a photo of one of the label's that would appear to have accompanied the piece on it's journey from Spain and likely from the mine too.

Who doesn't just want to eat Wulfenite? inadvisable I know, you would more than likely cut your mouth. Anyway these are photo's of the (Probably) Los Lamentos Wulfenite's from the thread.
https://www.mineral-forum.com/message-board/viewtopic.php?t=2587

[supertxango]

[nurbo]

Thanks Juan, Im glad the mystery is solved and label No 5 can be completed correctly.

Today Im posting a Sphalerite on Ankerite from the Old Carrs vein at the Smallcleugh Mine, this piece also has Brianyoungite on it, you can see it on the busted Sphalerite crystal on the very bottom of the piece.

then a very sharp looking Moscona Mine Calcite

and finally today Idocrase (or Vesuvianite) from Mexico, I have to assume these are etched due to the condition of the blue Quartz matrix.

[John S. White]

[nurbo]

Hello John,
Yep! Your right, it is in fact blue calcite, I fizzed it. Any idea's on what the white amorphous stuff is?

[Jordi Fabre]

[nurbo]

Thanks for correcting that Jordi.
Oh well, on with the show, two more piece's, first up an old sample of Barytocalcite from a little known locality in Cumbria, I trimmed this piece into a thumbnail. for the most part its Barytocalcite breccia but here and there you find little <20 mm vug's with very delicate white Barytocalcite crystal's in them and it trims up really easily..
I like these tiny little Vanadinite's on very white cockscomb Baryte, from Mibladen.

[nurbo]

I just edited the above photo's, turn's out Beldi Hill is actually in North Yorkshire close to the border with Cumbria.

I haven't had time to prepare any photo's but while Im here Ive got a couple of old one's

Firstly an unusual Baryte from Australia, maybe not unusual for the locality but unusual for me.

then whilst in Australia a Natrolite which I had to photograph in it's box due to it's fragility.

[nurbo]

Today I've done two more from the largest part of my collection, that being; boxed specimen's from North Yorkshire,
Firstly a Gypsum specimen from Mossdale Cavern's that just fit's corner to corner into a 6 cm box.
Second I've got a few of these and I used to think they were Aragonite var Floss Ferri but now I'm not so certain. I tried to fizz the actual central crystals, without getting any HCL on the surrounding carbonate matrix and they didn't show any sign of fizzing at all, the specimen is also a bit heavier than similar sized piece's from the same find and if you check the crystal form in the second photo and know the area a bit it seem's highly likely these are Baryte, the piece come's from a small dump near to Dam Rigg Level
. As always If anyone has any thought's either way I'd be very interested to hear them.

[nurbo]

I heard a tale today about why there will be no more of the Mossdale caverns Gypsum specimen's like the one from my previous post. In 1971 a group of 6 young cavers got into difficulties and drowned down there and the entrance was concreted shut, how terrible.

A Fluorite on Dolomite from a little seen location, The Dalefoot level at Mallerstang, the Fluorite's have lovely edge's and one has a black inclusion of something, Ive no idea what.
With Dolomite in mind here is a rather good Chalcopyrite on Dolomite from Wales.

[nurbo]

Im a particular fan of these green Sphalerite on Baryte from Judkins Quarry, I've only got a couple of samples but they are favourite's, I especially like the contrast between the green and the pinkish colour of the Baryte,
Another Baryte (or maybe not Baryte ) from Arkengarthdale, the more I look at these the more I'm convinced it is Baryte, which might be a bad thing because the more convinced I become the more I doubt I'm correct.

p.s. An amendment to the Mossdale Caverns tale ... The accident happened in 1967 but the entrance wasn't filled in till 1971, apparently it has been reopened to give access to much of the cave system but not the section where the cavers were entombed.

[nurbo]

I thought I repost these here after they were split off into another thread. I might not be 100 % sure what they are but whatever it is, they are among my very favourite pieces, they are so unusual and delicate,

[nurbo]

Hello,
A great new addition to my Ojuela collection and my Wulfenite collection too I guess. Wulfenite on Mottramite, it needs a bit of a clean but apart from that its perfect.

p.s. Does this really come from San Juan Poniente level 6 I can find no reference to Mottramite with Wulfenite from that bit of the mine complex ?

[nurbo]

I just got this Rampgill piece from the Boundary Cross vein, hard to photograph but a lovely assemblage of minerals. Im particularly interested by the two colours of Fluorite! there is a cluster and another crystal that are in contact with some Sphalerite that appear a kind of orangey yellow whereas the other Fluorite's on the piece are clear. Im thinking the colour has leeched into the cubes off the Sphalerite, also the prisms on the Quartz crystals are made of terminal faces which I didnt really capture too well in the photos.

[nurbo]

Another couple of Australian pieces, firstly Gold on Quartz from Kalgoorlie followed by a rather nice Baryte from Linkes Load.

[nurbo]

Wulfenite looks ever more edible to me.

[nurbo]

Today Ive done a Crocoite micro from Nontron in France and a Hemimorphite from the Precaucion Mine in Spain (Thanks Juan)

[nurbo]

A couple of classic northern English pieces today ...

I just took delivery of this excellent sample of reticulated Fluorite from the Old Towns Quarry, its a really fascinating piece, the Fluorites from some angles appear to be flattened octahedra.

This is a "Daisy Wheel" gypsum from Birkshead Mine, are these Cyclic twins?