Today,s item is a beautiful Rare piece of coal found in PennsylvaniaUSA it has a beautiful Natural Pattern to it
the size is 69x120x22 mm
Coal is one of the worlds major sources of energy. Coal is used to produce nearly one third of all the electrical energy that is generated and used in the United States. Coal is a very complex and diverse energy resource that can vary greatly, even within the same deposit. In general, there are four basic varieties of coal, which are the result of geologic forces having altered plant material in different ways.
Lignite: Increased pressures and heat from overlying strata causes buried peat to dry and harden into lignite. Lignite is a brownish-black coal with generally high moisture and ash content and lower heating value. However, it is an important form of energy for generating electricity. Significant lignite mining operations are located in Texas, North Dakota, Louisiana and Montana.
Sub bituminous: Under still more pressure, some lignite is changed into the next rank of coal, sub bituminous. This is a dull black coal with a higher heating value than lignite that is used primarily for generating electricity and for space heating. Most sub bituminous reserves are located in Montana, Wyoming, Colorado, New Mexico, Washington and Alaska.
Bituminous: Even greater pressure results in the creation of bituminous, or soft coal. This is the type most commonly used for electric power generation in the U.S. It has a higher heating value than either lignite or sub bituminous, but less than that of anthracite. Bituminous coal is mined chiefly