A Sotheby's employee holds a rare 52.82-carat white diamond ring at Sotheby's auction house on April 12, 2010 in London, England. Price: 7 million USD. (Photo by Dan Kitwood/Getty Images)

Anglers cast lines through holes into a frozen river during an ice fishing competition at the Hwacheon Sancheoneo Ice Festival on January 7, 2012 in Hwacheon-gun, South Korea. (Photo by Chung Sung-Jun/Getty Images)

Artist Will Ryman poses for photographs next to his installation entitled “The Bed” at the Saatchi Gallery in Chelsea on January 7, 2008 in London, England. (Photo by Chris Jackson/Getty Images)

Impala pictured in the Kruger National Park on December 7, 2007 in Mpumalanga, South Africa. (Photo by Warren Little/Getty Images)

The anthropometric record card of Sarah Giles, a servant who was convicted of stealing in 1897, on display making up part of a mosaic of cards on a table top during a press preview for the Crime Museum Uncovered exhibition at the Museum of London in the City of London, Wednesday, October 7, 2015. Drawn from Scotland Yard's private collection, the show charts more than a century of violence and suffering, from the murders of Jack the Ripper to IRA and al-Qaida bombings. But it also celebrates the brains, bravery and scientific advances that helped catch perpetrators and solve crimes. (Photo by Alastair Grant/AP Photo)

Chinese artist Kong Ning walks in her costume made of hundreds of orange plastic blowing horns during her art performance raising awareness of the hazardous smog in front of the Drum tower in a historical part of Beijing on a very polluted day December 7, 2015. Kong, whose works include themes related to China's air pollution problem, named her new performance “The Orange Horns Bride Marries the Blue Sky” and presented it dressed in orange, the colour of the second highest pollution alert level issued again in Beijing as hazardous smog blankets the capital. (Photo by Damir Sagolj/Reuters)

A Hindu holy man, or sadhu, smeared with ashes smokes marijuana in a chillum during the Shivaratri festival on the premises of Pashupatinath Temple in Kathmandu, Nepal, March 7, 2016. Hindu holy men from Nepal and India come to this temple to take part in the Maha Shivaratri festival. Celebrated by Hindu devotees all over the world, Shivaratri is dedicated to Lord Shiva, and holy men mark the occasion by praying, smoking marijuana or smearing their bodies with ashes. (Photo by Navesh Chitrakar/Reuters)