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.

A toque macaque is eating flowers in the water at the pilgrimage site in Polonnaruwa, Sri Lanka, on January 13, 2024. The toque macaque (Macaca sinica), a reddish-brown-colored Old World monkey, is endemic to Sri Lanka, where it is known as the rilewa or rilawa. It is named for the whorl of hair at the crown of its head, which resembles a brimless toque cap. (Photo by Thilina Kaluthotage/NurPhoto/Rex Features/Shutterstock)

Photographer David Emitt Adams creates tintypes on discarded cans he collects from the Sonoran Desert. In his artist statement, Adams says that some are more than four decades old, which have earned a deep reddish-brown, rusty coloration. (Photo by David Emitt Adams)

Born in 1958 in Kiev, Ukraine, artist Mark Khaisman studied Art and Architecture at the Moscow Architectural Institute in Russia. Now living in Philadelphia, USA, Khaisman uses rolls of brown packaging tape to create incredible works of art. Mark characterizes his work as ‘pictorial illusions formed by light and shadow’. The three key elements are: translucent packing tape, clear acrylic or film panels, and light. By superimposing layers of packaging tape Mark can ‘play on degrees of opacity that produces transparencies highlighted by the color, shading, and embossment’.

In this September 17, 2010 file photo a little brown bat is photographed in La Crosse Wis. Researchers for the first time found that little brown bats appear to be showing resistance to white-nose syndrome, which has killed millions of bats across North America. (Photo by Peter Thomson/La Crosse Tribune via AP Photo)

Kamchatka brown bears at Kurile Lake in Kamchatka peninsula’s volcanic terrain, Russia on August, 2017. Kamchatka brown bears are generally not dangerous to humans, and only 1% of encounters result in attack. (Photo by Igor Ivanko/Anadolu Agency/Getty Images)

Two brown bear cubs born at Whipsnade Zoo. (Photo by Evening Standard/Getty Images). 1970

A female brown bear with cubs fishing on Lake Kronotskoye as part of the South Kamchatka, Russia on Sanctuary, August 13, 2017. (Photo by TASS/Barcroft Images)