Bicycles of various bike-sharing services are seen at an urban village in smog during a polluted day in Shanghai, 2017. Rapid expansion of shared bicycle companies across China has led to massive piles of abandoned bikes as supply outstrips demand. (Photo by Aly Song/Reuters)

A municipal worker sits on a bench, next to a statue, in Nizhny Novgorod, Russia, during the 2018 soccer World Cup, Thursday, June 28, 2018. Nizhny Novgorod was a “closed city” during the Soviet era. It was known as Gorky until 1990 and it was here that dissident scientist Andrei Sakharov was held under house arrest. Now the city hosts six World Cup matches and is teeming with tourists. That was unthinkable in the Soviet era and even rare now in a city that is seldom visited by outsiders. (Photo by Vadim Ghirda/AP Photo)

Maksym Demchuk of Ukraine takes part in the FAI World Hot Air Balloon Championship near Gross-Siegharts, Austria on August 20, 2018. (Photo by Heinz-Peter Bader/Reuters)

Rhodochrosite is a manganese carbonate mineral with chemical composition MnCO3. In its (rare) pure form, it is typically a rose-red color, but impure specimens can be shades of pink to pale brown. It streaks white, and its Mohs hardness varies between 3.5 and 4. Its specific gravity is between 3.5 and 3.7. It crystallizes in the trigonal system, and cleaves with rhombohedral carbonate cleavage in three directions.

Women from a local cocoa farmers association called BLAYEYA work in a cocoa farm in Djangobo, Niable in eastern Ivory Coast, November 17, 2014. BLAYEYA is a women's only association with each member owning a field and planting cocoa. (Photo by Thierry Gouegnon/Reuters)

A Polish Air Force MIG-29 fighter (R) and an Italian Air Force Eurofighter Typhoon fighter patrol over the Baltics during a NATO air policing mission from Zokniai air base near Siauliai, Lithuania February 10, 2015. (Photo by Ints Kalnins/Reuters)

These adorable images of new born polar bears are bound to warm the hearts of even the biggest Ba-humbugs this Christmas. The stunning collection of photographs, taken over the space of ten years, manage to capture the tender bond between both mother and child as they emerge from their den for the very first time. Here: a Polar bear with its cub. (Photo by David Jenkins/Caters News)

A Cambodian resident wearing a mask attends a ceremony at Pring Ka-Ek village on the outskirts of Phnom Penh, Cambodia, 09 June 2016. Villagers organized a ceremony to continue their local traditions by paying respect to the Neakta Pring Ka-Ek (Spirit house) to prevent them from diseases and to achieve abundant rice harvests and other agricultural yields. (Photo by Mak Remissa/EPA)