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Identity HelpCan anyone identify these pieces.

18th May 2012 01:00 UTCCheryl Hurst

I feel a little foolish posting these, but don't have any idea what they are. I bought them at a thrift store so they didn't know anything about them. They are both encased in a block of some kind of plastic, I guess they are paper weights. Could they just be coal. I just found them to be interesting. Thanks for any help.

18th May 2012 09:05 UTCRock Currier Expert

They look like rough black rocks of some kind. Can't tell much more than that. They could be coal. Do they all appear to be the same stuff? You would have to cut one of the blocks open and run some tests on the stuff to have a better idea.

18th May 2012 10:55 UTCSpencer Ivan Mather

It looks like coal to me, and I can see the usual signs of pyrites on them!

Spencer

18th May 2012 18:21 UTCCheryl Hurst

Thanks, I was afraid that it was coal. After looking at images it looks like Anthracite. Maybe someone bought them in the gift shop at a coal mine.

18th May 2012 19:41 UTCPaul Brandes 🌟 Manager

Usually, anthracite coal does not have pyrite in it that looks like that. I do agree that the lighter coloured streaks look like pyrite, but whether it is in coal or some sort of metamorphosed rock is hard to tell just from the photos.

18th May 2012 20:13 UTCAnonymous User

Cheryl please don't ever feel foolish when asking a question if we don't ask we don't learn, and i ask more questions than most!;-) It would be nice to know if the black stuff burns and if so how quickly does.

18th May 2012 22:47 UTCCheryl Hurst

Unless you maybe drill holes into the block and try and bust it open there is no way to get inside. I added another picture of the blocks they are encased in to show the blocks better in case someone has seen something like this before. I just felt it a little odd to go to that much trouble for coal, unless it was a retirement gift for someone in the coal mining business. I live on the west coast so if coal they didn't come from here. When I typed in Anthracite and went to images a couple of pieces looked like these. Anyway thank you everyone for your help.

18th May 2012 23:57 UTCAnonymous User

It allways makes me chuckle a bit when i hear people being told coals are not very interesting, concidering the person saying it is nicely tucked up and warmed by it !

19th May 2012 02:07 UTCKeith A. Peregrine

These have some resemblance to petrified wood I collected this spring at the Mazonia Braidwood State & Fish Wildlife Area South Unit. The photos are not the best, but the petrified wood may contain a fair amount of coal (which can be fairly hard) and whitish-gold pyrite in thin veins or spread out. The pyrite can be quite bright as your samples show.

By the way, where is the thrift store located? If in northern or even central Illinois, then a Mazon Creek source is possible.

19th May 2012 02:27 UTCJim Bean 🌟

Cheryl, I'm pretty sure you have nailed it. It looks like coal embedded in lucite, probably prepared as a gift to present to someone who would have a greater appreciation of coal than most of us, say someone who gave many years in a mine or some such.

19th May 2012 02:31 UTCCheryl Hurst

I live in california and have never seen a piece of coal that I know of, and I'm 62 years old. Who knows maybe I have the only coal in the country encased in blocks that are suspended like they are. I'm happy with them, just really different looking. Thanks for all the help.

19th May 2012 03:33 UTCCheryl Hurst

I bought them in Vallejo California about 40 miles north of San Francisco. I live in Napa Valley had to go to Kaiser Hospital in Vallejo for a appointment for my husband and we stopped at a thrift store in Vallejo on the way, my husband was sweet enough to take me , we were going to a appointment for him about his 3rd time of cancer. Seen them and thought they looked different, and I will always keep them remembering his stopping for me to look around.

19th May 2012 12:32 UTCD Mike Reinke

Now there's a stocking stuffer for ya. Not just coal, but coal in plastic. Gotta feel the love there. lol!

Speculating on the origin of those pieces is amusing.

I suppose if you were really curious about their identity, you could weigh them, and get the volume. (Of a cube, that is pretty easy.) Compare that to a same size block of pure plastic (anybody out there know the specific gravity of lucite?) And you would at least know whether yours are somewhat lighter, then they'd probably be coal. Dark rocks, like amphiboles, have an SG of maybe 3. That may be a little more than the plastic, I'm not sure.

Either way, your reason for keeping them is priceless.

Thanks for sharing!

19th May 2012 18:38 UTCGeorge Eric Stanley Curtis

Cheryl,

It's just a passing thought, but most lumps of coal do not have visible pyrite in them. Pyrite produces sulphur fumes when burned, and I remember as a child with a coal fire in our front room, the fumes can be choking.

So it occurs to me that somebody may have preserved these lumps for the pyrite, rather than the coal.

To some people pyrite (fool's gold) is very attractive, but it soon tarnishes or gets dirty with coal dust, unless preserved as yours are.

As I say, just a thought, it might be the pyrite that was preserved, the coal was just the matrix.

It would be fascinating if you could trace their origin, and find out just why somebody went to all that trouble.:-S

Regards

Eric

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