Pronunciation: [d͡ʒˈɛt kˈə͡ʊl] (IPA) 
The correct spelling is "jet coal" and it is pronounced as /dʒɛt kəʊl/. Jet coal is a high-grade coal with a low ash content, which makes it ideal for jet fuel production. The word "jet" refers to the black color of the coal, which resembles the color of jet stone. The spelling of the word is straightforward, with the "j" sound represented by the letter "j" and the "e" in both words pronounced as a short "e".
Jet coal refers to a type of coal that is specifically used for the production of highly efficient, low-sulfur jet fuel. It is predominantly a hard, black rock-like substance that is primarily composed of carbon, along with varying amounts of other elements such as hydrogen, oxygen, sulfur, and nitrogen.
The term "jet coal" is derived from its specific application in the production of jet fuel, which is a high-energy, liquid fuel used to power jet engines. Jet coal is highly sought after due to its high carbon content, which makes it an excellent source of energy. Additionally, it possesses a relatively low sulfur content, making it suitable for the production of low-sulfur jet fuel.
The manufacturing process of jet coal typically involves extracting it from underground coal mines, followed by a series of refining steps to reduce impurities and increase its carbon content. These refinement processes may include crushing, washing, and heating the coal to remove undesirable substances and enhance its energy content.
Jet coal plays a crucial role in the aviation industry, as it is a key raw material in the production of jet fuel. Its utilization helps ensure the efficient and safe operation of jet engines, contributing to the smooth functioning of the global air transportation system. It is important to note that jet coal is distinct from other types of coal, such as thermal coal or metallurgical coal, as it is specifically tailored for the production of jet fuel.
The term "jet coal" seems to be a mistaken interpretation or combination of two different terms: "jet" and "coal". However, let's explore the etymology of each term separately:
1. Jet:
The word "jet" originated from the Old French term "jaiet" or "jaioit", which ultimately came from the Latin word "gagates". "Gagates" referred to a precious black stone thought to be found along the river Gagas in ancient Asia Minor. This stone, later known as "jet", was commonly used in jewelry and ornamentation due to its beautiful lustrous black appearance.
2. Coal:
The term "coal" comes from the Old English word "col", which is believed to have Germanic origins. In Old English, the word referred to all types of charcoal-like substances, including what we now call coal.
