Molybdenite Wires?

Has anyone seen molybdenite in a wire habit before? I know that pyrite can form wires and it is just another sulfide.



Thanks
Bob

Bob
I wouldn't think molybdenite would be strong enough to form a wire.
But who knows.
Wayne

Molybdenite tends to want to form platy crystals although as the crystals get bigger, you form bipyramidal crystals (the mineral structures of both polytypes tend to be planar). The conditions used to grow nanowires are unlikely to occur in nature [www.ncbi.nlm.nih.gov]

MoS2 and WS2 nanowires are the subject of a lot of current reserach both theoretically and experimentally. The closest thing I
know to molybdenite wires are micro molybdenite rolled cylinders from Mont Saint Hilaire. The specimen is in the Canadian Museum of Nature, and images were published in Mineralogical Record's MSH issue. I also got permission from
the photographer to republish the images in a book chapter I wrote. Recent attempts by
another scientist to contact the photographer to get permission to reprint the image have not been successful. Check out the MR issue.

A similar situation exists for graphite, which has related crystal structure, and should typically form platy crystals. Both graphite and molybdenite do form spheres too. I've not found molybdenite cones yet. Only one paper I know of shows
a purportedly natural graphite whisker (from Ticonderoga, NY).

John

Thanks all! John, when you say cones, do you mean a single cone - or cones stacked up on each other end on end to form something looking like a wire?

Thanks again!

Bob

In laboratory grown graphite, cones can be stacked up into a nano to micro wire, or they can wind around
and be stubbier like cones or a cigar.

In natural graphite from Gooderham, their internal structure is helical, but they do look like little cones.

Looks to me like you might have a whisker. They grow on several pure metals--e.g. tin, most famously.

Such whiskers are a significant threat to electronics, as they can grow and cause shorts between metal traces in microcircuits. It's one reason why the European ban on lead in solder has been a serious concern, as adding a bit of lead to the tin in solder suppresses whisker growth.

Sorry for the confusion Ray, the picture I posted is not the crystal in question, it is a filiform pyrite just as a demonstration.

Thanks John!

Bob

John,
If you need the SEM image of the tubuler molybdenite from MSH, please contact me. The specimen is in the CMN
collection but I have the SEM image made by a close friend.
Laszlo

John,

If you need the SEM image of the tubular molybdenite from MSH, please contact me. The specimen is in the CMN
collection but I have the SEM image(s) made by a close friend.
Laszlo
The strikeout appeared in the text above because of the [] brackets.

this is a great Question, Jessica
When I was a few years older than yourself, I found a real curiousity from the Dundas Quarry near Hamilton..It was little whisker like hairs
on the galena. I believed it to be filiform Galena, and took it to the Royal Ontario Museum and they confirmed it.

Bob
Can we see a photo of the crystal in question ?

Hi Lazlo,
I also still have a copy of the image and a digital version. I received an email a few years ago from a scientist in Europe who
wanted permission to use the image in a book or paper he was writing. Unfortunately we couldn't reach your friend for permission.
If your friend would give permission I could post the image on Mindat and also contact the scientist back.
THanks
John

Ray
Filiform galena sounds pretty interesting. I don't think I've heard of that before. Do you have any photos or SEM images?
John

Robert
I read in the Feb 2012 issue of Mineral News that wires of molybdenite have been identified in chabazite from
Merelani. Did you happen to study that? Unfortunately there was no image of it in the article. Hoping you can add
some details!

Cheers,
John

Yes the above question did indeed come from the work that Mike and
Jessica did, which led to the article in Mineral News and an abstract
submission to the Rochester Mineralogical Symposium. As for more
information, they are still being studied as there are a number of
unanswered questions. As we learn more, I will update you.

Bob