[Rockhounds] ID help

Tue Jun 23 14:33:37 PDT 2009

Hi Axel,

Trivalent chromium substituting for aluminum can (and does) cause red
fluorescence in topaz.  I don't have the paper handy, but I remember one
locality being given as Ghundao Hill (Afghanistan?).  As with corundum, a
quantity of chromium sufficient to cause red fluorescence will not
necessarily result in noticeable coloration of the mineral.  But I too would
like to know which UV wavelength causes the red fluorescence.

           cheers-   Earl

-----Original Message-----
From: rockhounds-bounces at lists.drizzle.com
[mailto:rockhounds-bounces at lists.drizzle.com] On Behalf Of Axel Emmermann
Sent: Tuesday, June 23, 2009 4:07 PM
To: 'Rockhounds at drizzle.com: A mailing list for rock and gem collectors'
Subject: RE: [Rockhounds] ID help

Could you state the UV-band? LW, SW, medium wave or blue light.... That
really matters ;-)))

Is that an "intense" fluorescence or rather weak or medium strong? 
Would you describe the red as "cherry" or more a "velvety" red?
Any "purple" in it or just plain red?

I think the topaz is out.... That would fluoresce yellow or whitish.
Diopside too, that would more likely fluoresce blue.
Ziosite is not likely to fluoresce... Except thulite, the manganoan zoistite
which fluoresces orange to pink.
Amblygonite??? Haven't heard of any fluorescence...

Corundum??? That is certainly a good candidate! The diamond-shaped
cross-section is indicative of that....

Don't discard the feldspars yet... but try a blue laser. If they fluoresce
REALLY hard in a blue laser beam then it is most likely corundum. A spectrum
would tell....

I tried the crystals that you sent me... even the blue "sapphire" fluoresces
in blue laser light!
If you stop and think about how the blue color is caused by iron... Iron
quenches fluorescence in many minerals. Still in blue laser light... I'll
try to make a photo, one of these days ;-)))))

OK, lI'll bet it's corundum.

Cheers

Axel

Axel Emmermann
European Regional Vice President of the
Fluorescent Mineral Society
<http://www.uvminerals.org/>
=========================
Mineralogische Kring Antwerpen/Antwerp Mineralogical Society
<http://www.minerant.org/index.html>
Werkgroepleider/Workgroup leader: Fluorescerende mineralen/Fluorescent
minerals
Technische Realisaties/Engineering
My website: http://users.telenet.be/axel.emmerman/FiatLux/Index.php

> -----Oorspronkelijk bericht-----
> Van: rockhounds-bounces at lists.drizzle.com
[mailto:rockhounds-bounces at lists.drizzle.com]
> Namens Lawrence Rush
> Verzonden: dinsdag 23 juni 2009 21:01
> Aan: Rockhounds at drizzle.com: A mailing list for rock and gem collectors
> Onderwerp: Re: [Rockhounds] ID help
> 
> Aha! They fluoresce a deep dark red! But, too hard for
> feldspar.......getting any closer, Axel?
> 
> Larry
> ----- Original Message -----
> From: "Axel Emmermann" <axel.emmermann at pandora.be>
> To: "'Rockhounds at drizzle.com: A mailing list for rock and gem collectors'"
> <rockhounds at lists.drizzle.com>
> Sent: Tuesday, June 23, 2009 2:51 PM
> Subject: RE: [Rockhounds] ID help
> 
> 
> > Larry,
> >
> > Topaz would have a distinct cleavage.
> > It breaks very easily in a plane that is perpendicular to the C-axis.
> > If you'd drop one of those hey would easily shatter and break at the
basal
> > plane.
> > I don't see that in you photos.
> > If I were to bet... some feldspar? Orthoclase? Microcline?
> > But zoisite and amblygonite are also possible...
> >
> > Any fluorescence?
> > Come on, Larry... make it shine ;-)))
> >
> > Cheers
> >
> > Axel
> >
> >
> > Axel Emmermann
> > European Regional Vice President of the
> > Fluorescent Mineral Society
> > <http://www.uvminerals.org/>
> > =========================
> > Mineralogische Kring Antwerpen/Antwerp Mineralogical Society
> > <http://www.minerant.org/index.html>
> > Werkgroepleider/Workgroup leader: Fluorescerende mineralen/Fluorescent
> > minerals
> > Technische Realisaties/Engineering
> > My website: http://users.telenet.be/axel.emmerman/FiatLux/Index.php
> >
> >
> >> -----Oorspronkelijk bericht-----
> >> Van: rockhounds-bounces at lists.drizzle.com
> > [mailto:rockhounds-bounces at lists.drizzle.com]
> >> Namens Lawrence Rush
> >> Verzonden: dinsdag 23 juni 2009 18:51
> >> Aan: rockhounds at lists.drizzle.com
> >> Onderwerp: [Rockhounds] ID help
> >>
> >> I just got a box of minerals from Pakistan which contained 2 pieces of
an
> > unidentified
> >> material. These are unfamiliar to me, and I need some help.
> >>
> >> The color is a sea green, translucent. The crystals are well formed,
> > appear to be perhaps
> >> Tetragonal or Orthorhombic. They have 4 distinct sides, diamond-shaped
in
> > cross section,
> >> with  sharp low angle edges on 2 sides. The hardness is greater than 6.
> > The matrix is quartz,
> >> evidently a pegmatite mineral. No locality, but all of the others from
> > this supplier were from
> >> Afghanistan, Pakistan, and Waziristan.
> >>
> >> I suspect they are Topaz, but the shape and color have me questioning
> > this.
> >>
> >> I posted photos on http://www.connroxminerals.com/temp.html
> >>
> >> Any thoughts?
> >>
> >> Thanks...Larry
> >>
> >>
> >>
> >>
> >> "Noel Coward thought work was more fun than play,  but he never, ever
> > worked in the mines"
> >>
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