[Rockhounds] flashing cleavages

[Axel Emmermann]

Hello people,

 

After having a technical issue resolved by the admin team in a very
professional way (my e-ternal gratitude for lifting me out of the depths of
e-solation) I'm back.

Some of you may have wondered why on earth I did not respond to the
"cleavage flash" issue. Well, I didn't get it but I got some mail indicating
that it would be worth taking a look at the archives of the messages of
around 12/1.

There it was:

CAVEAT: If you are easily offended, read no further. List owner (Julie) 
suggested that this post might be too racy for some.
 
Well Carolyn,
 
I finally dug out the hardness points and HCL and it looks you got it right
with calcite. Hardness of less that 3 and it bubbled like a Jacuzzi at a
cleavage flash party.
 
Thanks all! - John
Now that wasn't so bad was it?
 
From: "Carolyn Reynard" <
<http://lists.drizzle.com/mailman/listinfo/rockhounds> sunstone3 at
hvc.rr.com>
> Oh John,
> I should have explained "cleavage flash". I'll bet you were surprised and
> thought I was a bit bold. I had a good laugh over that one.
 

Indeed.

Carolyn: RESPECT. Never before in the 56 years that I'm around have I
witnessed an innocent slip of the keyboard of such proportion. 

John: Use Google Scholar next time. It will probably come up with the
mineral andersonite (Yes, like in Pamela Anderson who is a renown cleavage
flasher.)

Julie: I was rather "titillated" than offended (pardon my choice of words)

 

All that said, there's more to it.

 

When one cleave a mineral, one actually may produce a visible flash known as
triboluminescence. Quite a few minerals appear to have this quality. 

Sphalerite, clinohedrite and diamond to name a few.

Most people think that the sparks that you see when scratching such minerals
(or breaking them) are particle that burn up in the air. They are in fact
the binding energy between the crystal planes that is relaxing after tearing
them apart (by the millions with one pin-stroke).

 

Then there's fractoluminescence. In my opinion it was just another word for
triboluminescence but since it seems to apply for some kinds of glass (which
is non-crystalline) I needed to adjust my opinion.

Breaking the quite solid bonds between Si and O results in flashes of light
with energies of  1.9 to 2.7 eV. This is equivalent to 652.5 nm (red) to
459.2 nm (blue) light. 

 

Kreigh These Si-O bonds are quite strong. If the bonds in adhesive tape glue
were equally strong you would need dozens of horse-powers or more to peel of
an inch. Still that would only result in visible light, not even soft UV. So
indirectly, this cleavage flash redirects us to what you wrote on 10/24:
"Peeling tape is breaking a lot of bonds. That energy has to go 
somewhere. There is no need to invoke vacuum quantum fluctuations." No way
that you can get X-rays from breaking bonds. any bonds. I have some
possibles for this phenomenon. Maybe good for a new thread?
 
 
 

 

 

 

 

 

 

 

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

 



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