A woman wearing a mask reacts at her garden which locates next to chimneys of coal-fired power plant in Shijiazhuang, Hebei province, China, January 28, 2015. Beijing introduced tougher regulations this year to combat pollution, keen to overhaul China's unwanted image of smog-choked cities, fouled waterways and heavy-metal tainted soil. (Photo by Kim Kyung-Hoon/Reuters)

Schoolchildren play music to entertain and inspire people on their way home from work Tuesday, March 29, 2016 in Pyongyang, North Korea. North Korea has called a 70-day loyalty drive areas of a major congress of the ruling party scheduled for early May and everyone from students to coal miners have been mobilized nationwide to demonstrate their devotion to the leadership. (Photo by Eric Talmadge/AP Photo)

Medics help a rescued miner after an explosion and fire at a coal mine killed at least 17 miners and left up to 300 workers trapped underground, in Soma, in western Turkey, Tuesday, May 13, 2014, a Turkish official said. Twenty people were rescued from the mine but one later died in the hospital, Soma administrator Mehmet Bahattin Atci told reporters. The town is 250 kilometers (155 miles) south of Istanbul. The death toll was expected to rise. (Photo by AP Photo/Depo Photos)

“The 1926 general strike in the United Kingdom was a general strike that lasted nine days, from 4 May 1926 to 13 May 1926. It was called by the general council of the Trades Union Congress (TUC) in an unsuccessful attempt to force the British government to act to prevent wage reduction and worsening conditions for coal miners”. – Wikipedia

Photo: Oxford University Student Volunteers during the General Strike in an aggressive pose. (Photo by Fox Photos/Getty Images)

The mineral pyrite, or iron pyrite, also known as fool's gold, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of fool's gold. The color has also led to the nicknames brass, brazzle, and Brazil, primarily used to refer to pyrite found in coal.
In crystallography, the cubic (or isometric) crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals.

A view of the Hazelwood Power Station across the cooling pondage at sunrise on March 21, 2012 in Melbourne, Australia. The brown coal fueled power station, located in Latrobe Valley is the oldest in Victoria and provides the state nearly 25% of its energy. In 2005 Hazelwood was labeled Australia's least carbon efficient power station by WWF Australia and continues to be a target of issue of environmentalist groups. (Photo by Hamish Blair/Getty Images)

Student, Shoukria positions a stone for cutting at the Turquoise Mountain Gem cutting class on May 18, 2011, in Kabul, Afghanistan. The mineral resources of Afghanistan are relatively unexplored even with Afghanistan's mineral wealth of coal, copper, gold and iron ore, with precious and semiprecious stones, including high-quality emerald, lapis lazuli, red garnet and ruby. Given the country's remote and rugged terrain, on-going instability plus an inadequate infrastructure and transportation means that mining is still difficult. While many are trying to bring positive changes, Afghanistan's mining industry uses unregulated, primitive methods and outdated equipment. (Photo by Paula Bronstein/Getty Images)

Peasants in the re-taken Somme District work in the fields, circa 1916- 1917, in this Library of Congress handout photo. For women 100 years ago, opportunities to work beyond the home and take part in political life were very limited. As the 20th century progressed, hard-won progress included gradually improved voting rights, while the upheaval of war pushed doors ajar as women worked as part of the war effort. U.S. Library of Congress archive photos show women's workplaces ranging from a flour mill in England to a coal mine in Belgium or Lincoln Motor Co.'s welding department in Detroit. International Women's Day is celebrated on March 8. (Photo by Reuters/Bain Collection/Library of Congress)