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Identifing an Unknown Mineral


#1

I know from reading posts over the last few months, that this is the
place to go when help is needed for just about anything. Thank you for
being here and so willing to help. I know it is very hard to identify
anything by pictures but we would be interested to see what you all
think.

Yesterday, we acquired a collection of minerals from a man who just
got tired of moving them around. Most were readily identifiable.

The one in the photos (link provided) The blue crystals were covered
with a green copper looking material. We removed the material with
water and a toothbrush. We uncovered these vibrant blue crystals,
There are also quartz crystals, and it looks like chocopyrite that is
weathered, and some very small dark blue crystals that look like
azurite. It is about 4 inches by 3 inches high and the blue crystal
cluster on top is about 2 " by 2". The crystals have striations and
appear to be etched.Also, the crystals are very rounded. And the
piece does not fluoresce…

We have never seen anything like this rock, and would appreciate any
insight anyone could offer.

We know absolutely nothing about the location or origin

The photos are here:


Thanks again for any help.
Lynn & Harold


#2

The blue crystals in your pictures appear to be a mineral called
chalcanthite, otherwise known as copper sulphate pentahydrate, which
is very suluble in water. Chalcanthite can occur naturally in arid
regions but much of it forms as a result of mining.


#3
http://www.ganoksin.com/ftp/mineral-1.jpg
http://www.ganoksin.com/ftp/mineral-2.jpg 

Hi,

Judging by the jpegs and the copper association your mystery mineral
looks exceedingly like a copper sulphate. Natural copper sulphates
can occur as brochantite (Cu4SO4{OH}6) or antlerite Cu3SO4{OH}4 or
chalcanthite (CuSO4.5H2O). All are soluble in water; all are found
in the oxidized portion of copper deposits especially in desert
regions. It’s likely not antlerite because that is green.

Unless you can get a provenance it has little value as a specimen;
and so you might try scraping a bit of the material from an
inconspicuous corner, dissolving it in water, and then putting a few
drops of the solution on a steel knife blade. It should copper-plate
the steel.

Cheers,
Hans Durstling
Moncton, Canada
www.virtualfundy.com


#4

Lynn and Harold,

The specimen looks a lot like lazulite in matrix from Grave’s
Mountain, Georgia. The crystal shape (bipyramidal) and matrix color
is right, only I have not seen lazulite in a cluster, or that
translucent. From a book, Linarite is translucent blue like your
specimen.

Jeff Simkins
Cincinnati, OH


#5

Sure looks like Chalcanthite, the natural mineral form of ordinary
copper sulphate. Most “mineral specimins” of the stuff are fakes, as
the crystals are easily grown on almost any substrate mineral. It’s
water soluable, making it easy to both test, and damage…

Just a guess…
Peter


#6

this looks to be a form of cuprite … or cuperous sulfate… I am
favoring the latter!!!

DM


#7

http://www.webmineral.com/

This is the most incredible site - thousands of mineral photos, and
properties. Just during breakfast, I searched for “blue”. Some
likely hits were Kinoite, Cavansite, Chalcomenite, and #1 - Papagoite
looks much like your photo. You can do more, though, because you have
the specimen and can look into crystalline structure, cleavage,
streak, etc. It’s a cool site for
all, though, too.


#8

Wow, that is a stunning specimen. Maybe it’s some sort of blue
chalcedony?

Yes, technically I know that ALL quartzes are members of the
chalcedony family, but the blue variety that is actually commonly
known as chalcedony, I mean. In any case, it’s lovely!

Jennifer


#9
   and so you might try scraping a bit of the material from an
inconspicuous corner, dissolving it in water, and then putting a
few drops of the solution on a steel knife blade. It should
copper-plate the steel. 

Hans

Thank you everyone who responded.

You were on the money here, we dissolved some in water and put it on
a knife blade and it really did copper-plate it.

So I have concluded that this was lab created, and near worthless,
although it is very pretty to look at…

Thanks again,
Lynn


#10
    Yes, technically I know that ALL quartzes are members of the
chalcedony family, but the blue variety that is actually commonly
known as chalcedony, I mean. In any case, it's lovely! 

Actually…it’s the other way around… Chalcedony is a
cryptocrystalline member of the quartz species…

And a species within a species to boot……

Gary W. Bourbonais
A.J.P. (GIA)


#11

Hi Jennifer,

   Yes, technically I know that ALL quartzes are members of the
chalcedony family, but the blue variety that is actually commonly
known as chalcedony, 

Not to be nit picking, but to be technically correct, chalcedonies
are part of the Quartz family, not the other way around.

Dave