German field telegraph operators at work in Warsaw. (Photo by Hulton Archive/Getty Images). 1st October 1914

A model poses beside the Porsche Hybrid during the media day of the Shanghai International Automobile Industry Exhibition at Shanghai New International Expo Center on April 19, 2011 in Shanghai, China. The 14th Shanghai International Automobile Industry Exhibition (Auto Shanghai 2011) will be held from April 21 to 28 with the theme of “Innovation For Tomorrow”. About 2,000 carmakers and parts providers from 20 countries are due to showcase 1,100 car models, 75 of which makes their world premieres in the auto show. (Photo by Feng Li/Getty Images)

A man stands next to his giant pumpkins as he waits for them to be weighed in at the 34th Annual Safeway World Championship Pumpkin Weigh-Off October 8, 2007 in Half Moon Bay, California. (Photo by Justin Sullivan/Getty Images)

A participant jumps on vintage skis during a traditional historical ski race in the northern Bohemian town of Smrzovka, Czech Republic, February 20, 2016. (Photo by David W. Cerny/Reuters)

Patsy Gibbons takes his two rescue foxes, Grainne and Minnie (unseen), for a walk in Kilkenny, Ireland April 25, 2016. Gibbons nursed the foxes back to health after they were found abandoned as injured cubs, and they have stayed with him since. (Photo by Clodagh Kilcoyne/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)

Carlos Martinez (L), a representative of the Guinness World Records, examines the cooking process of a chocolate coin during an attempt to break the Guinness World Record for the biggest chocolate coin in Caracas, Venezuela, October 1, 2015. More than 80 people will work with 100% Venezuelan cacao to create the coin that is estimated to weigh 1,000 kg, according to local media. (Photo by Carlos Garcia Rawlins/Reuters)