A two-horse team street cleaner, with sprayer, squeegee, and roller at rear. New York, between ca. 1910 and ca. 1915. (Photo by NYC Municipal Archives)

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.

Rob Maitland of Australia collects a ball from the ocean during warm-up for the Water Polo by the Sea match between Australia and the United States of America at at Bondi Icebergs on Bondi Beach on January 4, 2012 in Sydney, Australia. (Photo by Mark Kolbe/Getty Images)

African migrants stranded in Costa Rica walk near garbage on the Inter-American highway at the border between Costa Rica and Nicaragua, in Penas Blancas, Costa Rica, September 8, 2016. (Photo by Juan Carlos Ulate/Reuters)

An alligator is pictured stuck in the mud of the dry Pilcomayo river, which is facing its worst drought in almost two decades, on the border between Paraguay and Argentina, in Boqueron, July 3, 2016. (Photo by Jorge Adorno/Reuters)

Jeepney passengers are seated in between plastic barriers, wearing face masks and face shields mandatory in public transportation, in Quezon City, Metro Manila, Philippines, August 19, 2020. (Photo by Eloisa Lopez/Reuters)

A woman holds her veil as she takes part in Huranga, a game played between men and women a day after Holi, at Dauji temple near Mathura, March 3, 2018. (Photo by Adnan Abidi/Reuters)

Shannon Courtenay exchanges punches with Buchra El Quaissi during the Bantamweight between Shannon Courtenay and Buchra El Quaissi at York Hall on December 19, 2019 in London, England. (Photo by James Chance/Getty Images)