A zoo worker feeds milk to tiger cubs born on the first day of the Lunar New Year and Year of the Rooster at Sriracha Tiger Zoo in Chonburi province, Thailand, January 30, 2017. (Photo by Athit Perawongmetha/Reuters)

A Zombie Santa is pictured Death Yard Haunted Attraction in Hendersonville, Tennessee December 10, 2014. The Nashville-area haunted house is getting into the Christmas spirit this weekend, with Zombie Santa, his undead elves and a demonic reindeer going on the attack for fun and charity. (Photo by Harrison McClary/Reuters)

In this photo taken on Saturday, November 16, 2013, Mt. Etna, Europe's most active volcano, spews lava during an eruption as seen from Acireale, near the Sicilian town of Catania, Italy. (Photo by Carmelo Imbesi/AP Photo)

The mineral pyrite, or iron pyrite, also known as fool's gold, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of fool's gold. The color has also led to the nicknames brass, brazzle, and Brazil, primarily used to refer to pyrite found in coal.
In crystallography, the cubic (or isometric) crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals.

Stumpy the lemur has just turned 27 and is believed to be the oldest ring-tailed lemur in the world. He's still loving life, according to Zoo keepers. (Photo by Hemedia/Swns Group)

A customer grimaces in pain as she gets a tattoo on her arm at the 21st International Tattoo Convention Berlin on December 3, 2011 in Berlin, Germany. The annual tattoo trade fair runs from December 2–4, 2011. (Photo by Adam Berry/Getty Images)

U.S. President elect Barack Obama kisses his wife Michelle as Vice-President elect Joe Biden (right) embraces his wife Jill after Obama gave his victory speech during an election night gathering in Grant Park on November 4, 2008 in Chicago, Illinois. (Photo by Scott Olson/Getty Images)

Pretty Girls, Ugly Faces is a photo fad in which girls take pictures of themselves while posing in an unflattering manner, making a silly face or performing a physically strenuous activity.