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.

Baldwin Street, in Dunedin, New Zealand, is considered the world's steepest residential street. It is located in the residential suburb of North East Valley, 3.5 kilometres (2.2 mi) northeast of Dunedin's city centre.

Wedges of an orange generate enough current and electrical juice – 3.5 volts – to power an LED. The fruit’s citric acid helps electrons flow from galvanized nails to copper wire in this 14-hour exposure. This image was published in September’s Visions of Earth, a trio of photos that appear in each issue of National Geographic. (Photo by Caleb Charland/National Geographic)

A boy looks for scrap metal using an improvised magnetic tool near a construction site in New Delhi, India, March 21, 2016. (Photo by Cathal McNaughton/Reuters)

In the works of a photographer named Dave – who goes by Freaktography and never gives out his full name – haunting abandonment leaps from images of discarded machinery, tools and factory essentials. (Photo by Freaktography/Caters News Agency)

Hikaru Cho believes that we should challenge our imaginations to create new work using traditional tools, not fancy computers and software. (Photo by Jim Marks/PA Wire)

Folk artist Han Xiaoming demonstrates painting with his tongue in Hangzhou, Zhejiang province December 4, 2014. Han dips his tongue in ink to paint on paper, and uses his fingers to fill in final adjustments. The artist also uses a paintbrush held with his mouth and utilizes fish and vegetables as paint tools, local media reported. (Photo by Aly Song/Reuters)