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  2. Coal - Wikipedia

    en.wikipedia.org/wiki/Coal

    Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements , chiefly hydrogen , sulfur , oxygen , and nitrogen . [ 1 ]

  3. Bituminous coal - Wikipedia

    en.wikipedia.org/wiki/Bituminous_coal

    Bituminous coal. Bituminous coal, or black coal, is a type of coal containing a tar-like substance called bitumen or asphalt. Its coloration can be black or sometimes dark brown; often there are well-defined bands of bright and dull material within the seams. It is typically hard but friable.

  4. Prices of chemical elements - Wikipedia

    en.wikipedia.org/wiki/Prices_of_chemical_elements

    Chlorine, sulfur and carbon (as coal) are cheapest by mass. Hydrogen, nitrogen, oxygen and chlorine are cheapest by volume at atmospheric pressure. When there is no public data on the element in its pure form, price of a compound is used, per mass of element contained. This implicitly puts the value of compounds' other constituents, and the ...

  5. Jet (gemstone) - Wikipedia

    en.wikipedia.org/wiki/Jet_(gemstone)

    Jet is a type of lignite, [1] the lowest rank of coal, and is a gemstone.Unlike many gemstones, jet is not a mineral, but is rather a mineraloid. [2] It is derived from wood that has changed under extreme pressure.

  6. Glossary of coal mining terminology - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_coal_mining...

    Small coal at one time referred to charcoal, but this usage is obsolete. [31] Snap or bait. Snap, bait or piece is food taken to eat part way through the shift and often carried in a snap tin. [32] Sough. A sough is a drainage tunnel to take water from coal mines without the need to pump it to the surface. [1] An example is the Great Haigh ...

  7. Anthracite - Wikipedia

    en.wikipedia.org/wiki/Anthracite

    Other terms which refer to anthracite are black coal, hard coal, stone coal, [10] [11] dark coal, coffee coal, blind coal (in Scotland), [7] Kilkenny coal (in Ireland), [10] crow coal or craw coal, and black diamond. "Blue Coal" is the term for a once-popular and trademarked brand of anthracite, mined by the Glen Alden Coal Company in ...

  8. Why is it called Black Friday? Here's the real history behind ...

    www.aol.com/news/why-called-black-friday-heres...

    According to the History Channel, the name was first used to describe an 1869 financial crisis, in which corruption and stock fraud caused the U.S. gold market to collapse entirely.

  9. History of coal mining - Wikipedia

    en.wikipedia.org/wiki/History_of_coal_mining

    Coal prices fell in the 1980s, partly in response to oil price movements, but primarily in response to the large increase in supply worldwide which was brought about by the earlier price surge. During this period, the industry in the U.S. was characterized by a move towards low-sulfur coal. [68] In 1987 Wyoming became the largest coal producing ...