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Identity HelpBlack Fuzzy Mineral - Pyrolusite? Locality?

15th Nov 2014 00:23 UTCIan Whitlock

I came across a few of these strange minerals in my grandpa's garage, and I'm not quite sure what they are. I was told that they could be Pyrolusite, but no one I've talked to knows 100% for sure what they are. If it is Pyrolusite, then does anyone know where its from?

Thanks for your help!

-Ian

15th Nov 2014 00:26 UTCDon Saathoff Expert

Looks like hollandite from Luis Lopez claims in Socorro Co., NM but you can never be sure because it is a fairly common mineral....

15th Nov 2014 01:04 UTCPeter Haas

The fibers appear to be translucent and non-metallic. Please have a closer look at them in person and tell us how they look like.

15th Nov 2014 01:53 UTCJohn Sobolewski 🌟 Expert

I agree with Don that they look like the Hollandite/Romanechite specimens found in the Luis Lopez Claims a few miles south of Socorro. There is a paper that the needles consist of thin alternate layers of Hollandite and Romanechite. John S.

15th Nov 2014 02:11 UTCJohn Krygier

I have a half dozen similar pieces, labeled as "psilomelane" on "pyrolusite" from Socorro Co.

http://www.mindat.org/gallery.php?loc=3992&min=3304

Also as pyrolusite: http://www.mindat.org/gallery.php?loc=3992&min=3318

I have seen it called "Rat's Hair".

John K.

15th Nov 2014 02:28 UTCMark Heintzelman 🌟 Expert

Both of mine are from the Nancy claim rather than the Luis Lopez, both sites produced very nice specimens. And John, thanks for making note of that paper. I've had mine labeled as "psilomelane" in quotes, as I was a bit suspicious about them being pure romanechite.

MRH

15th Nov 2014 02:53 UTCDoug Daniels

Back in the 70's, before the better analysis, the stuff was called "rat's hair psilomelane". It is very delicate, so try not to brush it or otherwise disturb the "hairs".

15th Nov 2014 03:14 UTCJohn Sobolewski 🌟 Expert

John,

In the 1990's when I collected similar specimens, many people called them "Rat's Hair Psilomelane" but when I checked at the Museum of Minerals at the New Mexico Institute of Mining and Technology (a mineral museum well worth visiting), I was told by the then Curator of Minerals that the "Rat's Hair" needles that had been analyzed from the Luis Lopez Manganese District proved to be a combination of alternate layers of Hollandite and Romanechite. I have the paper somewhere but cannot put my hands on it right now. John S.

15th Nov 2014 04:05 UTCIan Whitlock

Thanks a lot everyone! I appreciate the help. Ive never heard of Psilomelane before today, but thats definitely what this is.

15th Nov 2014 04:53 UTCDoug Daniels

This may be the article: "Mineralization in the Luis Lopez mining district, Socorro County, New Mexico - a summary" by Robert North & Virginia McLemore, in Guidebook to the Socorro Area, New Mexico, 1987 (published by the New Mexico Bureau of Mines & Mineral Resources). This Guidebook was for the 24th meeting of the Clay Minerals Society and the 36th annual Clay Minerals Conference; it may be available online at geoinfo.nmt.edu, I haven't checked myself.

16th Nov 2014 23:24 UTCPaul Brandes 🌟 Manager

Those are nice hairs of Psilomelane/Romanechite, Ian! (tu)

It's quite rare to find/have an undamaged specimen; what's the size on it?

17th Nov 2014 03:09 UTCIan Whitlock

That one is only about an inch but I have some bigger one's too. Ill post a couple more pictures of them

17th Nov 2014 03:25 UTCIan Whitlock

OK, Heres some pictures of the rest of my Psilomelane's

The Big one in the Box is 5.1cm x 3.7.

The Smallest one is 2.4cm x 1.9cm

17th Nov 2014 05:49 UTCDoug Daniels

I remember fellow students collecting flats of this stuff, and trying to sell it......not much luck, cuz it was black and "ugly". And, the mine itself was dangerous, mostly from "bad air" (depleted oxygen).

17th Nov 2014 06:00 UTCIan Whitlock

Ya, its definitely not the most aesthetic mineral out there, but its just kind of cool to have. I found it in my grandpa's garage so i know it can't be worth much at all.

30th Aug 2015 00:14 UTCKenneth Moore

Would you be willing to trade the largest one outside of the box? As common as people say it is, I can't seem to find them...

10th Dec 2018 01:01 UTCSusie Eash

I just today purchased a piece of Hollandite=Romanechite at the Earth Treasure Show in Los Alamos. The dealer was a very old man (with his daughter) who told me that he rockhounded many of these himself years ago outside of Socorro, NM. I was looking at and purchasing other crystals at their table and the daughter was pulling more rocks out from under the table to replace things that had sold. She plopped the Hollandite-Romanechite right in front of me and I said, "What is that???" Father and daughter both related to me how they had gone hunting for this near Socorro and how delicate the crystals are and how it made them totally black. There's no information online about this combo rock. All I can say is that when the daughter plopped it down in front of me today, I said, "If Stevie Nicks were a crystal, this is what she would be. Black velvet and top hat over a hard interior. This Hollandite-Romanechite is the crystal equivalent of Rhinannon. And also I heard Pearl Jam's "Black". That black is a deeper black of anything I've anything I've ever seen. Powerful juju in Hollandite-Romanechite.

Edit: Welcome to Mindat, Susie! You are welcome to post messages, but please refrain from using profanity in the messageboards. Thank you.

10th Dec 2018 02:47 UTCKevin Conroy Manager

These are/were found in a number of places. Analysis has shown that they are a mix of hollandite and romanechite, so "psilomelane" is the best name to use. As for some locations, please see: https://www.mindat.org/gallery.php?loc=3992&min=3304

10th Dec 2018 05:04 UTCDoug Daniels

I would agree - the Luis Lopez Manganese district. Picking a specific mine, good luck. I collected there as a student in the late 70's. And, as Kevin said, (unless you send a piece for analysis), best to just call it "psilomelane" (and, if it looks furry, it has the adjectives "rat's hair", tho I have yet to see a black rat).

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