50 free Coal trivia questions with answers — science & nature quiz, new questions added Aug 2026.
Coal is compressed swamp: plants that died 300 million years ago, buried and cooked until only carbon was left. It powered the Industrial Revolution, still makes a third of the world's electricity and is the biggest single source of carbon dioxide. These coal trivia questions cover the geology, the ranks, the mines, the safety lamps and canaries, the disasters, the smog and the strikes. Every answer is sourced, with a short explanation so you learn something even when you miss.
30 of 50 questions with answers and explanations. Play the quiz
Q 01What kind of rock is coal?
Sedimentary
It forms in layers called seams as buried peat is cooked by heat and pressure over millions of years.
Q 02What do decaying plants become first, before heat and pressure turn them into coal?
Peat
Most modern peat bogs formed about 12,000 years ago after the last ice age.
Q 03Which geologic period is literally named 'coal-bearing'?
Carboniferous
The name comes from the Latin carbo and fero, coined by William Conybeare and William Phillips in 1822.
Q 04Roughly what share of all coal beds were laid down in just two geologic periods?
90%
Atmospheric oxygen above 30% and forests full of slow-rotting lignin helped pile up the peat.
Q 05Which is the highest rank of coal?
Anthracite
It has the most carbon, the fewest impurities and the highest energy density, and is mostly burned for heating.
Q 06Which soft, low-rank coal is often called 'brown coal'?
Lignite
The name comes from the Latin for wood, and it comes out of the ground full of moisture.
Q 07What is the approximate carbon content of the highest-rank coal?
86–97%
Brown coal sits at about 25–35% carbon, which is why it gives so little heat per tonne.
Q 08Which rank of coal is the most abundant on Earth?
Bituminous
It is burned for electricity and, when low in sulfur and phosphorus, turned into coke for steelmaking.
Q 09Which US state holds the world's largest known deposits of the highest-rank coal?
Pennsylvania
The Coal Region of the northeast holds an estimated seven billion short tons.
Q 10Why was the trademarked brand 'Blue Coal' actually blue?
It was sprayed with dye at the mine
Glen Alden Coal Company wanted its product to stand out from competitors in Northeastern markets.
Q 11What is the key distinction between thermal coal and metallurgical coal?
Electricity versus steelmaking
Thermal (steam) coal raises steam for power; metallurgical (coking) coal is burned at high heat to make steel.
Q 12How is coke made from coal?
Heating it without air
It serves as both fuel and reducing agent when smelting iron ore in a blast furnace.
Q 13Which geological rule says that, locally, deeper coal is higher in rank?
Hilt's law
It holds when the thermal gradient is vertical; an igneous sill can break it, as at Madrid, New Mexico.
Q 21About what share of world coal production comes from surface mining?
40 percent
The earth removed above a seam is called overburden and is dumped in long strips.
Q 22What is the rock and soil removed to expose a coal seam called?
Overburden
When the ratio of overburden to coal gets too high, mines switch to augering into the highwall.
Q 23Which underground method accounts for about half of all underground coal production?
Longwall mining
A shearer works a face of 300 metres or more while hydraulic supports advance with it and the roof falls behind.
Q 14What did Neolithic people in Shenyang carve from black brown-coal around 4000 BC?
Ornaments
By 1000 BC coal from the Fushun mine was being used to smelt copper.
Q 15What was the Old English form of the word 'coal'?
col
It traces back to a Proto-Indo-European root meaning 'live coal'.
Q 16About what share of the world's electricity did coal supply in 2020?
Over a third
It also provided roughly a quarter of global primary energy that year.
Q 17Which country mines almost half the world's coal?
China
It produces about 4.8 billion tons a year; India is next at roughly a tenth.
Q 18Which two countries export the most coal?
Indonesia and Australia
Russia is the next-biggest exporter.
Q 19Roughly how many tonnes of carbon dioxide came from burning coal in 2024?
15 billion
That was more than a quarter of all global greenhouse gas emissions.
Q 20Which 2021 agreement committed countries to 'phasing down' coal?
The Glasgow Climate Pact
Meeting the Paris 2 °C target requires halving coal use between 2020 and 2030.
Q 24In room and pillar mining, what holds up the roof?
Unmined coal
The pillars can contain up to 40 percent of the seam; 'retreat mining' later pulls them out.
Q 25Up to how many vertical feet of mountain are blasted away in mountaintop removal mining?
400
The excess rock goes into neighbouring valleys as 'holler fills', mostly in Appalachia.
Q 26Which region is the largest coal-producing area in the United States?
Powder River Basin
Straddling Wyoming and Montana, in 2007 it out-produced the entire Appalachian region.
Q 27What is the explosive mine gas known as firedamp?
Methane
A firedamp blast can set off a far deadlier coal-dust explosion through the whole mine.
Q 28Who invented the gauze-screened miners' safety lamp in 1815?
Humphry Davy
Engine-wright George Stephenson demonstrated a rival lamp at Killingworth Colliery a month earlier.
Q 29Which future railway pioneer built a competing safety lamp in 1815?
George Stephenson
His design let air in through tiny holes; the Royal Society paper on Davy's lamp came a month later.
Q 30Which 1812 disaster near Newcastle, killing 92 men, spurred the push for safer mine lamps?
Felling
Clergymen Robert Gray and John Hodgson wrote to Davy asking him to tackle firedamp explosions.