An aerial view shows the 11/19 pit and twin slag heaps at the former coal mine site in Loos-en-Gohelle, northern France, November 1, 2015. Loos-en-Gohelle, a town of 7000 inhabitants in the North of France, marked by the closure of coal mines in 1970, has demonstrated a successful transition from coal to a green economy. (Photo by Pascal Rossignol/Reuters)

Wang Zhengqing, a 74 year old pneumoconiosis patient, smokes his pipe at Yangjia Hospital in Wuyi County, Zhejiang Province, China October 19, 2015. Former miner Wang was diagnosed with the disease, which is caused by dust inhalation, when he was 24 and has lived at Yangjia Hospital for ten years. (Photo by Damir Sagolj/Reuters)

A donkey carrying sacks of coal walks through the narrow tunnels of a coal mine, in Choa Saidan Shah in Punjab province April 29, 2014. Coal miners in Chao Saidan Shah use donkeys to transport coal from the depths of the mines to the surface. (Photo by Sara Farid/Reuters)

38 year old Prabhat Sinha, from Assam, carries a load of coal weighing 60kg's, supported by a head-strap, as he ascends the staircase of a coal mine on April 16, 2011 near the village of Khliehriat, in the district of Jaintia Hills, India. (Photo by Daniel Berehulak/Getty Images)

Ray Collins is a colorblind Australian coal miner who is in love with the ocean. He spends his off days photographing it. Collins says he enjoys capturing the moment before the moment, the anticipation, not knowing how the end of the wave's journey will play out. (Photo by Ray Collins)

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 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.

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)