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Rueb
10-03-2010, 04:23 PM
Got a few marcasite from a friend in germany.

Here they are:
http://img832.imageshack.us/gal.php?g=img8846.jpg

Rueb
10-08-2010, 01:52 AM
I tried to split them up into smaller pieces but to no avail.
How would you try to accomplish that?

Rueb

theFool
10-08-2010, 12:52 PM
Here they are:
http://img832.imageshack.us/gal.php?g=img8846.jpg
Nice speciments, and big ones. Children usually hit them between two rocks to reveal their shiny interior, but you could use a heavy hammer I guess.

Dendritic Xylem
10-08-2010, 02:08 PM
I tried to split them up into smaller pieces but to no avail.
How would you try to accomplish that?

Rueb


Do an ebay search for "sore thumb crusher".

You could easily make your own if you or a friend has a welder and cutting torch laying around.

It looks like the ones on ebay are painted on the inside of the tube as well.
I'd try to get that out to avoid contamination of the mineral sample.

Rueb
10-11-2010, 05:09 PM
OK the heavy hammer did the job.

This was the upper right marcasite.
In real it looks like a shiny grey metal for now.

http://img530.imageshack.us/gal.php?g=img8851p.jpg

theFool
10-11-2010, 06:24 PM
OK the heavy hammer did the job.
Nice. Over time, it will develop a white dust on the broken surface.

Rueb
10-14-2010, 06:49 PM
I think I will reduce them to even smaller pieces, medium sized grains. It is supposed to fall apart during the putrefaction in the air but in order to see this, medium sized grains are probably the best solution to speed up this "effect". If I powder it right away it will probably be best but I wont see the decomposition as described.

The appearance of the white dust, our mercury, do you know that by experience or is that some information out of books your read, theFool?

Rueb

Rueb
11-01-2010, 11:06 AM
Here the pictures of the salt spoken of:

http://img502.imageshack.us/gal.php?g=img8584i.jpg

You have to enlarge them to see it.


Rueb

theFool
11-01-2010, 02:10 PM
The appearance of the white dust, our mercury, do you know that by experience or is that some information out of books your read, theFool?
Sorry, missed the post. By experience, I have seen it in one old broken speciment I had. I don't know about mercury produced by that and haven't read about that in any other book.

The white dust is described in wikipedia:

Marcasite reacts more readily than pyrite under conditions of high humidity. The product of this disintegration is iron(II) sulfate and sulfuric acid. The hydrous iron sulfate forms a white powder consisting of the mineral melanterite, FeSO47H2O.[5]

This disintegration of marcasite in mineral collections is known as "pyrite decay". When a specimen goes through pyrite decay, the marcasite reacts with moisture in the air, the sulfur combining with water to produce sulfuric acid that attacks other sulfide minerals and mineral labels. Low humidity (less than 60%) storage conditions prevents or slows the reaction.[6]

From another site:

Marcasite may go through a condition known as pyrite decay, in which a specimen slowly disintegrates into a white powder. Little is known about this detrimental condition. It only effects certain Marcasite specimens at random, while other specimens remain unaffected. When a specimen goes through pyrite decay, the sulfur atoms free themselves and form an acid that attack other sulfide minerals and mineral labels. It is most important to remove an afflicted specimen from other minerals, to prevent this "disease" from spreading.

Rueb
11-01-2010, 04:30 PM
from Glauber:

Take this Ore or Minera beaten into pieces, and for some
space of time, lay or expose it to the cool air, and within
twenty or thirty days it will magnetically attract a certain
saltish moisture out of the air, and grow heavy by it, and at
last it falleth asunder to a black powder, which must remain
further lying there still, until it grow whitish, and that it do
taste sweet upon the tongue like vitriol.

Rueb
11-01-2010, 04:50 PM
From another site:

Marcasite may go through a condition known as pyrite decay, in which a specimen slowly disintegrates into a white powder. Little is known about this detrimental condition. It only effects certain Marcasite specimens at random, while other specimens remain unaffected. When a specimen goes through pyrite decay, the sulfur atoms free themselves and form an acid that attack other sulfide minerals and mineral labels. It is most important to remove an afflicted specimen from other minerals, to prevent this "disease" from spreading.

I put this marcasite outside since the whole last full moon period. And I will leave it outside. Away from the sun and rain.
Also quite some dew gathered on them which dried during the daytimes.

Also some pieces seems to oxidize seen here:

http://img101.imageshack.us/i/img8589s.jpg/

Rueb

Seth-Ra
11-01-2010, 09:55 PM
Rueb, are you referring to the golden shade in the pic as the oxidation? I find it interesting, because i tried an experiment with normal table salt in a dish, added a little rain, and let it dry in the sun, dew would gather on it at night, and dry during the day again, done this for about a week, and it bit by bit began to "degrade" or something, a golden powder formed in it. I re-crystalized the salt, the golden matter doesnt seem to fuze with it (per se) and it stayed on top of it so i have held onto it for a while. A couple nights ago i decided to add all of it to some dew i had caught and circulate it, after a few hours i noticed the golden powder stuff wasnt water soluble and looked more like a red powder. (it wasnt rust from the original dish either, i tested for that, and the powder tastes a bit earthy if at all). *also the term "golden powder/matter" is only referring to its color. ;) *

I could be wrong, but i wonder if there is a connection - i.e. something the dew and sun/moon are doing, or making, depositing it on/in minerals as magnets for this substance.... :)



~Seth-Ra

Rueb
11-02-2010, 05:48 PM
Rueb, are you referring to the golden shade in the pic as the oxidation?

Yes, I can't comment on your golden powder though.

Rueb

Rueb
05-24-2011, 09:23 PM
hmmm the old pictures are gone ...

anyway here is a new one:

http://imageshack.us/f/593/img9223t.jpg/

It's interesting to note that this white crust appeared over night. It also vanished again the day after.
I had that happen in that amount 3 times now. Nailed down to 3 thunderstorms (one with hail).
I let the rain fall into the dish for a while. I just made sure not to let it overflow which would of course spoil it.

On a normal day just a few small crystals are seen which also vanish depending on the moisture.

The vanishing part is simply humidity which dissolves the crust it seems.

Rueb