Definition - What does Oil Shale mean?
Oil shale consists of sedimentary rock that contains kerogen, which is a combination of organic compounds from which shale oil can be extracted through heating. Through further processing, shale oil can be converted into crude oil.
Safeopedia explains Oil Shale
Shale oil is abundant around the world and the United States has large shale oil reserves. However, extracting and processing shale oil is expensive and has significant negative impacts on the environment. The shale can also be burned in furnaces in order to generate power and heating, but it is a low-grade form of fuel when used in this way. China, Estonia, Brazil, Germany and Russia all have established oil shale industries. Apart from environmental impacts, the high cost of using this source of fuel currently makes exploiting it largely impractical.