Revellers pose during the 24th Street Parade dance music event in Zurich, August 29, 2015. (Photo by Arnd Wiegmann/Reuters)

Crocoite is a mineral consisting of lead chromate, and crystallizing in the monoclinic crystal system. It is identical in composition with the artificial product chrome yellow used as a paint pigment.

Iranian skiers rest at the Dizin ski resort, northwest of Tehran January 15, 2016. (Photo by Raheb Homavandi/Reuters/TIMA)

A masked reveller poses in San Marco Piazza during the Venice Carnival, January 30, 2016. (Photo by Alessandro Bianchi/Reuters)

A clothing shop displays its merchandise in the rebel-controlled city of Idlib, Syria November 7, 2015. (Photo by Ammar Abdullah/Reuters)

A family dressed in traditional chinese clothes celebrates the Chinese New Year in Chinatown in Bangkok, Thailand February 8, 2016. (Photo by Jorge Silva/Reuters)

A man rides a motorcycle along a street in the snow in Altay, Xinjiang Uighur Autonomous region, February 9, 2016. (Photo by Reuters/Stringer)

Clouds gather as walkers pause atop a ridge in Mountain View, California January 7, 2016. (Photo by Noah Berger/Reuters)