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I found these rocks in my yard.
Protoss Dragoon:
--- Quote from: Cappytaino on June 16, 2017, 02:59:51 AM ---If there was an iron mine nearby, these rocks are likely slag. A Hematite or similar ore will often show signs of oxidation and denudation (being reddish-brown in color) whereas these appear to have a dull metallic luster and are dark grey in color, indicating they're likely a byproduct of the smelting process which contains some iron but not enough to oxidize like a Hematite would.
If you really want to figure it out, see if it is at all magnetic, and if possible perform a Mohs Hardness test. An iron product or ore would be much harder than anthracitic coal iirc.
You could also try to determine if there is any striation of different materials in the slag, or chip off a piece to try to see crystalline structure if any.
A coal would also burn so you could try that as well.
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Thanks for the helpful info!, I can write with these rocks, they leave dark trails when enough friction is added to them.
I'll see if it's magnetic in the morning, I'm too tired right now to do anything besides type.
Cappytaino:
--- Quote from: Protoss Dragoon on June 16, 2017, 05:15:01 AM ---Thanks for the helpful info!, I can write with these rocks, they leave dark trails when enough friction is added to them.
I'll see if it's magnetic in the morning, I'm too tired right now to do anything besides type.
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If you can write with them, it sounds it could be a kind of coal; higher grade coals (i.e. anthracite and obviously graphite) will leave a trail when rubbed across paper. An anthracite would ignite relatively easily, while a graphite usually does not. The law of superposition would lead me to believe that if you found these on top of or in the A horizon of the soil, they are relatively new, so they could possibly be either slag or mined coal that just got dropped at some point, as the coal could have been used to fire the pig iron forges to make the intermediary product between a mined iron ore and steel.
Anthracitic coal will have a hardness of 2.75-3 on the Mohs scale, meaning that you should easily be able to scratch it with a fingernail or a copper coin i.e. a penny. Graphite would be even softer, you could probably scratch graphite with a fingernail. Slag would be harder than anthracite, meaning you'd need a steel file or knife to scratch it.
Here's a Mohs chart for reference.
Plethora:
The slag I've seen tends to have pits and pockets in it, almost like a sponge. Maybe not all of it's like that, but I'd put my money on it being some kind of coal.
Protoss Dragoon:
--- Quote from: Cappytaino on June 16, 2017, 12:19:17 PM ---If you can write with them, it sounds it could be a kind of coal; higher grade coals (i.e. anthracite and obviously graphite) will leave a trail when rubbed across paper. An anthracite would ignite relatively easily, while a graphite usually does not. The law of superposition would lead me to believe that if you found these on top of or in the A horizon of the soil, they are relatively new
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I found these around a foot or two in the ground while digging, some where higher and lower than the other rocks.
--- Quote from: Plethora on June 16, 2017, 01:30:37 PM ---The slag I've seen tends to have pits and pockets in it, almost like a sponge. Maybe not all of it's like that, but I'd put my money on it being some kind of coal.
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These rocks are very smooth with no pits and pockets
Protoss Dragoon:
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Anthracitic coal will have a hardness of 2.75-3 on the Mohs scale, meaning that you should easily be able to scratch it with a fingernail or a copper coin i.e. a penny. Graphite would be even softer, you could probably scratch graphite with a fingernail. Slag would be harder than anthracite, meaning you'd need a steel file or knife to scratch it.
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The rocks were easily scratch able, leaving a line where I tested the scratch test.