Industrial or basaltic ?

I found this today among suface deposits above the Cleveland Dyke north east England, my question is have i found industrial waste ie furnace glass or remnants of the molten basaltic andasite coming into contact with existing materials?
The piece under a microscope shows crystals on the concretions including what looks like hematite, and there are hair like white formations in some of the darker stuff.

Unless there are very recent basaltic flows in that part of England it look like you may have found a piece of industrial slag.

Rock Currier
Crystals not pistols.

I thought it might be but the hairs i mentiond under a scope ive found are called Pele's hair and belong in basaltic glass also under the scope the tubular glass has a wood like grain again as in basaltic glass dose this happen in industrial stuff ?



Edited 2 time(s). Last edit at 05/08/2012 10:11PM by Heath Barnes.

Ps the attatchments in the last page are examples not my piece but are very simmiler to what ime seeing under the scope

Closer pic of tubes ?

Rock Currier Wrote:
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> Unless there are very recent basaltic flows in
> that part of England it look like you may have
> found a piece of industrial slag. Could it be possible that becouse the dyke never reached the surface 57 mya the stuff it came into contact with was preserved to look recent ?

It looks slaggy to me Heath, and slag is very common and light weight,so it sits on top. Notice all the air bubbles. Only pumice has air bubbles, if stuff really is 500myo, geologic forces tend to do away w/ air bubbles. plus, if it were weathered any number of years, the miosture at earths' surface would leach out some iron, and make the rock look brown. The ropy-ness ( a word?) would seem to me to be the molten glass in the slag, not exactly pahoe pahoe lava like in Hawaii. Around here, slag is used as ballast in the railroad bed, especially under the not-so-heavy commuter train tracks. Just my guess for you.

I'm sorry, but that is a piece of slag. Some positive indicators that I see right away is the shiny-ness of the broken "tubes" in DSCF1135-001 and I would bet it is quite light for its size, correct Heath?? To me, it doesn't look like any of the pahoehoe or aa lava flows that you would find on Hawai'i, or a normal specimen of pumice or scoria either, and certainly nothing like you'd find on a 58 Ma dyke; it just doesn't have the correct appearence.

Even if the dyke never reached the surface, it still would have been chewed on by ground water, and delicate tubes would not survive the weathering that would eventually expose the specimen at the surface. But you can tell only so much from photos. If it is that important to you, pay to have it tested.

Rock Currier
Crystals not pistols.

Hello Heath,
Welcome to Mindat. This is slag - both coal and ironstone furnaces produce slag like this, and ironstone was mined all around that area of Yorkshire. Yes, hairs that look like Pele's hair are found in slag. In fact, modern mineral wool is produced using slag by mimicking the formation of Pele's hair: air is blown over molten slag, in the same manner that winds blow over molten basalt in Hawaii. The Cleveland dyke shows microscopic amounts of glass in the groundmass, but nothing tachylitic (glassy like obsidian) has been found, as far as I know. Becky

Thanks for the input all, firstly the piece is heavy 1kg with a 300ml volume, also there are very few vesecals also ime very familier with the waste that is produced from the huge steel industry we have and it does not look or feel like the average slag we have round here, also ive found plenty of pink tuff in the same area, the red material matches similer found in Tachylite found in abundance in other areas to the north west of here all related to the same activity 57 mya, while ime on with the dyke subject this is not the first time ive found what should not be there, the basaltic andesite here is magnetic ie it does not just deflect a compas needle it easily attracts a weak magnet.

Becky Coulson Wrote:
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> Hello Heath,
> Welcome to Mindat. This is slag - both coal and
> ironstone furnaces produce slag like this, and
> ironstone was mined all around that area of
> Yorkshire. Yes, hairs that look like Pele's hair
> are found in slag. In fact, modern mineral wool
> is produced using slag by mimicking the formation
> of Pele's hair: air is blown over molten slag, in
> the same manner that winds blow over molten basalt
> in Hawaii. The Cleveland dyke shows microscopic
> amounts of glass in the groundmass, but nothing
> tachylitic (glassy like obsidian) has been found,
> as far as I know. Becky Thanks for that becky ps its Cleveland not Yorkshire We are proud of our older place name here.

D Mike Reinke Wrote:
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> It looks slaggy to me Heath, and slag is very
> common and light weight,so it sits on top. Notice
> all the air bubbles. Only pumice has air bubbles,
> if stuff really is 500myo, geologic forces tend
> to do away w/ air bubbles. plus, if it were
> weathered any number of years, the miosture at
> earths' surface would leach out some iron, and
> make the rock look brown. The ropy-ness ( a
> word?) would seem to me to be the molten glass in
> the slag, not exactly pahoe pahoe lava like in
> Hawaii. Around here, slag is used as ballast in
> the railroad bed, especially under the
> not-so-heavy commuter train tracks. Just my guess Thanks Mike yes we used it round here to reclaim land for the docks. and it covers lots of the tracks around here. But it don't look like this stuff or weigh nearly as much maybee its some kind of slag ive never walked on before ?
> for you.

Another vote for slag.

Can anyone explain why its so heavy ?

If I get your stats right, the specific gravity is around 3.3, right? Quartz and glass run a little less than 3, say, 2.6 or7, basalt runs 3 to 3.3, right? So this isn't terribly heavy, but I have found that that little bit of higher SG is very deceptive in my hand. i've pick up stream rocks, especially softball size and larger and thought 'wow! this is serious stuff!' only to find it's SG is 3+ a little, and it is probably an amphibole, not exactly platinum(missed again!)
It is probably heavy because of the iron, SG of over 7. Anything dark, esp. as dark as that piece, i chalk up to iron. Does this sound plausible?

Mike my last post was in reply to me being told it was slag and therfore why was a by product from a furnace so heavy, correct me if ime wrong but i thought that the whole idea of a steel works was to extract the heavy stuff ?