Sparks are thrown as an employee grinds the edges of a ski at the plant of Swiss ski manufacturer Stoeckli in Malters, Switzerland November 25, 2015. Stoeckli plans to produce some 1,000 pair of skis per year of a special edition for Swiss watch manufacturer TAG Heuer, a brand of LVMH Group. (Photo by Arnd Wiegmann/Reuters)

A train drives along a field at a salt production site at the Sasyk-Sivash lake near the city of Yevpatoria, Crimea, November 14, 2017. A saltwater lagoon known as Lake Sasyk-Sivash on Ukraine's Crimea peninsula is the source of a rare resource: pink salt. The mineral is tinted by tiny algae that produce the pigment beta-carotene. Each autumn, seasonal workers collect thousands of tons of pink salt for processing and export. (Photo by Pavel Rebrov/Reuters)

Blacksmith Johann Schmidberger works on a suit of armour for the Vatican's Swiss Guards at his workshop in Molln, Austria, March 29, 2017. Austrian blacksmiths who produce ceremonial suits of armour for the Vatican's Swiss Guards are close to the end of their current deal to do so, and say supplying the suits will not now be an issue for many years to come. One of the drawbacks of the Swiss Guards' medieval uniforms is that the craftsmanship needed to make them is disappearing. (Photo by Leonhard Foeger/Reuters)

The Tree Projects team spent 67 days documenting one eucalyptus regnans in the Styx valley of Tasmania. Using a combination of tree-climbing and elaborate arboreal rigging techniques, they produced an intimate portrait from an impossible perspective of one of the world’s largest individual flowering trees, which goes by several common names. These photos document the process that resulted in an extraordinary ultra high-definition photograph. Here: Haley nears the top of the tree. (Photo by Steven Pearce/The Tree Projects/The Guardian)

A illegal gold miner of Kamoro people, Tinus, pan for gold on February 4, 2017 in Timika, Papua Province, Indonesia. Indonesia produces over 70 billion dollars in gold a year and is home to the largest gold mine and the third largest copper mine in the world, the Grasberg mine, which is located at West Papua. (Photo by Ulet Ifansasti/Getty Images)

A sun bear reacts to triple-digit temperatures at the Henry Doorly Zoo in Omaha, Nebraska, where the temperature reached 103 degrees Fahrenheit on July 6, 2012. (Photo by Nati Harnik/Associated Press)

Masked women shout slogans during a demonstration marking the Latin American Day for Decriminalization of Therapeutic Abortion in Managua, Nicaragua, where abortions are illegal, on September 28, 2012. (Photo by Esteban Felix/Associated Press)

People ride a motorcycle near Koudoukou Mosque where Pope Francis meets Imam Tidiani Moussa Naibi in Bangui, Central African Republic, November 30, 2015. (Photo by Stefano Rellandini/Reuters)