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Author Topic: Was it coal?  (Read 4921 times)

Offline Make it Lady

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Was it coal?
« on: 25/05/2009 22:37:23 »
Some kids found some coal in the woods near us but when we looked at it, it didn't act completely like coal. It didn't mark paper when you rubbed it and it felt like plastic. Otherwise it broke up like coal and looked like coal so was it coal?


 

Offline RD

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Was it coal?
« Reply #1 on: 25/05/2009 23:19:38 »
It didn't mark paper when you rubbed it and it felt like plastic.
 Otherwise it broke up like coal and looked like coal so was it coal?

Anthracite ? (a hard form of coal)



Quote
Anthracite differs from ordinary bituminous coal by its greater hardness, its higher relative density of 1.3-1.4, and luster, which is often semi-metallic with a mildly brown reflection. It contains a high percentage of fixed carbon and a low percentage of volatile matter. It is also free from included soft or fibrous notches and does not soil the fingers when rubbed.
http://en.wikipedia.org/wiki/Anthracite
« Last Edit: 25/05/2009 23:22:48 by RD »
 

Offline frethack

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Was it coal?
« Reply #2 on: 26/05/2009 01:02:13 »
My guess would be anthracite as well.  Looks and feels like plastic and generally wont leave much of a mark.
 

Offline JimBob

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Was it coal?
« Reply #3 on: 26/05/2009 16:12:47 »
The question

"so was it coal?"

Coal is fossil swamps and/or peat bogs - high organic deposits of the leaf, fern, algae, moss, extinct plants, etc., - swamp flora that existed in the past.

Coal comes in grades that are dependent on their depth of burial and thus the pressure and temperature they have endured.

    * Peat, considered to be a precursor of coal, has industrial importance as a fuel in some regions, for example, Ireland and Finland.
    * Lignite, also referred to as brown coal, is the lowest rank of coal and used almost exclusively as fuel for electric power generation. Jet is a compact form of lignite that is sometimes polished and has been used as an ornamental stone since the Iron Age.
    * Sub-bituminous coal, whose properties range from those of lignite to those of bituminous coal are used primarily as fuel for steam-electric power generation. Additionally, it is an important source of light aromatic hydrocarbons for the chemical synthesis industry.
    * Bituminous coal, dense mineral, black but sometimes dark brown, often with well-defined bands of bright and dull material, used primarily as fuel in steam-electric power generation, with substantial quantities also used for heat and power applications in manufacturing and to make coke.
    * Anthracite, the highest rank; a harder, glossy, black coal used primarily for residential and commercial space heating. It may be divided further into metamorphically altered bituminous coal and petrified oil, as from the deposits in Pennsylvania.
    * Graphite, technically the highest rank, but difficult to ignite and is not so commonly used as fuel: it is mostly used in pencils and, when powdered, as a lubricant.

(I'm too damned lazy to write all of the coal grades so went to http://en.wikipedia.org/wiki/Coal and nabed the grade description there.)

I will add that graphite is known from Pre-Cambrian rocks (more than 650 Million Years old and before plants existed,) Here in Texas it is found in the Packsaddle Schist suite of rocks. The Mezoproterozoic mined deposit are about 60 miles from where I live on the east side of Lake Buchanan in central Texas. This deposit has been heavily mined but are now shut down. Other methods for producing graphite - as a manufacturing by-product - are less expensive. (The mine pit is over 150 feet deep and is now filled with water.)
« Last Edit: 26/05/2009 16:21:42 by JimBob »
 

Offline Make it Lady

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Was it coal?
« Reply #4 on: 26/05/2009 17:38:49 »
Thanks all. These are the best answers I've ever had on this Forum and no one laughed at me, once! I shall tell the kids.
 

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Was it coal?
« Reply #4 on: 26/05/2009 17:38:49 »

 

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