[Rockhounds] Help! Has anyone ever seen or heard of blackTorbernite?

[Kreigh Tomaszewski]

Thanks Axel! And in interesting website too.

All the references I had for Metatorbornite just listed it as dark 
green, and this is definately black.

Kreigh


On Sunday, Mar 15, 2009, at 05:57 America/Detroit, Axel Emmermann wrote:

> Kreigh,
>
> I found a reference that may make sense:
> http://www.uraniumminerals.com/UTh/M-Torbernite.htm
>
> Meta-torbernite is sometimes nearly black and occurs as a pseudomorph 
> after
> torbernite. There are several degrees of dehidratation and it appears 
> that
> the color (pale green to almost black) is greatly influenced by 
> formation
> process.
>
> Axel
>
>
>
>> -----Oorspronkelijk bericht-----
>> Van: rockhounds-bounces at lists.drizzle.com
> [mailto:rockhounds-bounces at lists.drizzle.com]
>> Namens Kreigh Tomaszewski
>> Verzonden: zondag 15 maart 2009 4:39
>> Aan: Rockhounds at drizzle.com: A mailing list for rock and gem 
>> collectors
>> Onderwerp: [Rockhounds] Help! Has anyone ever seen or heard of
> blackTorbernite?
>>
>> Hey List,
>>
>> I recently acquired two specimens of Torbernite from Bendada Quarry in
>> Portugal. Both of the specimens are mostly beautifully formed, bright
>> green, torbernite crystals, up to 6 mm, standing on edge, in a
>> beautiful patchwork coating. I have absolutely no doubt about the
>> Torbernite identification for the green crystals.
>>
>> However, both specimens have a portion that is covered with what looks
>> like black torbernite crystals. On both specimens there are a few
>> crystals that are half green and half black.
>>
>> I've never heard of black torbernite. I'm guessing a pseudomorph, but
>> what the heck could it be? Torbernite without the Uranium? What would
>> that be?
>>
>> I did find one Torbernite specimen for sale from the quarry that
>> included Nsutite (which is not listed by Mindat for the locality) as a
>> black secondary mineral, but it doesn't make sense chemically to me.
>>
>> Do any of you experts have a suggestion for what I have acquired in a
>> trade? I want to make a good label, but I'm stumped.
>>
>> Kreigh
>>
>>
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