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  2. Lignite - Wikipedia

    en.wikipedia.org/wiki/Lignite

    Lignite mining, western North Dakota, US (c. 1945). Lignite is brownish-black in color and has a carbon content of 60–70 percent on a dry ash-free basis. However, its inherent moisture content is sometimes as high as 75 percent [1] and its ash content ranges from 6–19 percent, compared with 6–12 percent for bituminous coal. [5]

  3. Organic-rich sedimentary rocks - Wikipedia

    en.wikipedia.org/wiki/Organic-rich_sedimentary_rocks

    Organic-rich sedimentary rocks may act as source rocks which generate hydrocarbons that accumulate in other sedimentary "reservoir" rocks [2] (see oil sands and petroleum geology). Potential source rocks are any type of sedimentary rock that the ability to dispel available carbon from within it (limestone is a classic example of a source rock ...

  4. Bituminite - Wikipedia

    en.wikipedia.org/wiki/Bituminite

    The value of bituminite increases with grade. At high grade, i.e. high maturity, bituminite has high hydrogen to carbon content [citation needed]. A high hydrogen/carbon ratio bituminite indicates a good hydrocarbon source. However, low grades of bituminite vary depending on type, meaning that there is variable hydrogen/carbon ratios. [1]

  5. List of rock types - Wikipedia

    en.wikipedia.org/wiki/List_of_rock_types

    The following is a list of rock types recognized by geologists.There is no agreed number of specific types of rock. Any unique combination of chemical composition, mineralogy, grain size, texture, or other distinguishing characteristics can describe a rock type.

  6. Coal analysis - Wikipedia

    en.wikipedia.org/wiki/Coal_analysis

    The fixed carbon content of the coal is the carbon found in the material which is left after volatile materials are driven off. This differs from the ultimate carbon content of the coal because some carbon is lost in hydrocarbons with the volatiles. Fixed carbon is used as an estimate of the amount of coke that will be yielded from a sample of ...

  7. Jet (gemstone) - Wikipedia

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

    Jet is around 75% carbon and 12% oxygen with sulfur and hydrogen making up most of the balance. [7] Other elements are found at trace level and the exact ratios varying with the source; for example, Spanish jet contains more sulfur than Whitby jet. [7] Jet has a Mohs hardness ranging between 2.5 and 4 and a specific gravity of 1.30 to 1.34.

  8. Sedimentary rock - Wikipedia

    en.wikipedia.org/wiki/Sedimentary_rock

    Sedimentary rocks are laid down in layers called beds or strata. A bed is defined as a layer of rock that has a uniform lithology and texture. Beds form by the deposition of layers of sediment on top of each other. The sequence of beds that characterizes sedimentary rocks is called bedding.

  9. Leonardite - Wikipedia

    en.wikipedia.org/wiki/Leonardite

    It is an oxidation product of lignite, associated with near-surface mining. [1] It is a rich source of humic acid (up to 90%) [ 2 ] and is used as a soil conditioner , as a stabilizer for ion-exchange resins in water treatment, [ 3 ] in the remediation of polluted environments and as a drilling additive. [ 4 ]