Rock
Coal
Kömür
Swamp forests turned to stone: the fuel of the Industrial Revolution, still burnt today for electricity and steel.
- Industrial
- Important in Türkiye
In short
Coal is a black or brown rock that burns. It formed from plant remains that piled up in swamps millions of years ago and were buried and squeezed by heat and pressure. It is not a mineral: it has no fixed chemical formula or crystal structure and is made of organic matter from plants. Burning it releases a lot of energy, but it also pollutes the air and gives off carbon dioxide, which drives climate change.
How does it form?
Coal begins in warm, wet swamp forests. Dead trees and plants pile up in oxygen-poor swamp water without fully rotting and form peat. As the peat is buried under more sediment it is compressed, loses water and gases, and its carbon content rises. This process is called coalification: peat turns first into lignite and then, under deeper and hotter conditions, into sub-bituminous coal, bituminous coal and finally anthracite. The higher the rank, the harder and shinier the coal and the more heat it gives when burnt.
What is it used for?
- Electricity: Most of the world’s coal is burnt in power stations.
- Steel: Coke made from certain bituminous coals is used to smelt iron ore in blast furnaces.
- Heating: It is still burnt as fuel in many homes and cities.
Burning coal releases carbon dioxide, sulfur dioxide and fine dust, which makes it one of the main causes of air pollution and climate change.
Coal in Türkiye
In Türkiye, hard coal is mined only in the Zonguldak basin on the Black Sea coast. Most of the coal mined in the country is lignite, and the largest lignite basin is Afşin-Elbistan in Kahramanmaraş. Because most Turkish lignite has a low calorific value, much of it is burnt in power stations.
How to recognise it
- 1
It is black or dark brown and surprisingly light for its size.
- 2
Rubbed on unglazed porcelain it leaves a black or brown streak, and many kinds blacken your hands.
- 3
Most kinds show alternating bright and dull bands; lignite sometimes shows woody texture.
- 4
It burns, giving off smoke and a distinctive smell. Anthracite is shinier and harder than other coals and hardly soils the hands.
Fakes and imitations
What shops usually don’t tell you:
- Barbecue charcoal is not coal in the geological sense; it is made by heating wood without air.
- Coke is a manufactured fuel made by heating coal without air; it is porous and silvery grey.
- Jet and Erzurum's Oltu stone, used in jewellery, are also coalified wood, but they are far more compact than ordinary coal and take a polish. Black plastic and glass can imitate them.
Safety
Coal mining is dangerous: methane (firedamp) can build up in mines and explode, and coal dust breathed in over many years can cause pneumoconiosis (“black lung”), a permanent lung disease. Coal stoves at home need good ventilation, because coal that does not burn completely produces carbon monoxide, an odourless and deadly gas.
Did you know?
The Carboniferous Period is named after its many coal-bearing rock layers; the word means “coal-bearing” in Latin.
At the Joggins Fossil Cliffs in Canada you can see upright fossil tree trunks between coal seams, left from swamp forests that grew about 300 million years ago.
Where is it found?
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- Zonguldak hard-coal basin, Türkiye · Major depositThe basin between Ereğli and Amasra is the only place in Türkiye where hard coal is mined. Its complex geology makes production underground and labour-intensive.
- Afşin-Elbistan, Kahramanmaraş, Türkiye · Major depositTürkiye's largest lignite basin; its low-calorific-value lignite is burnt mainly in power stations.
- Zollverein, Essen, Germany · Historic sourceFormer coal mine and coking plant in the Ruhr; inscribed on the UNESCO World Heritage List in 2001.
- Joggins Fossil Cliffs, Nova Scotia, Canada · Known localityCarboniferous coal seams with upright fossil tree trunks record the swamp forests of the “Coal Age”; inscribed on the UNESCO World Heritage List in 2008.
Locations are approximate to protect sites. Red dots mark places in Türkiye. Open in the big map →
Sources
- Coal · Encyclopaedia Britannica
- Country profiles: Türkiye · EURACOAL
- Kömür Arama Araştırmaları · MTA Genel Müdürlüğü
- Coal Resource Classification System of the U.S. Geological Survey (Circular 891), Table 2 · U.S. Geological Survey, 1983
- Zollverein Coal Mine Industrial Complex in Essen · UNESCO World Heritage Centre
- Joggins Fossil Cliffs · UNESCO World Heritage Centre
External links
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