Albert Lleal / Orpiment, a sulphide of arsenic, from Greece

Jack Dykinga / A travertine formation in the Grand Canyon, known as Pumpkin Springs, where hot arsenic waters created a pool next to the Colorado River. Grand Canyon National Park, Arizona. May 2012.

Ernie Janes / Geothermal area, Wai-O-Tapu, North Island, New Zealand, January 2009

Ernie Janes / Champagne Pool, Wai-O-Tapu geothermal area, North Island, New Zealand, January 2009

Ernie Janes / Geothermal area, Wai-O-Tapu, North Island, New Zealand, January 2009

Ernie Janes / Aerial view of sulphur mineral deposits in Orakei Korako Volcanic Valley, North Island, New Zealand

Colin Monteath / Rain storm approaches Champagne Pool, volcanic lake has constant 74 degree Celsius water including minerals gold, silver mercury, sulphur, and arsenic, Wai-O-Tapu Thermal Wonderland, Rotorua, North Is...

Colin Monteath / Rain storm approaches Champagne Pool, volcanic lake has constant 74 degree Celsius water including minerals gold, silver mercury, sulphur, and arsenic, Wai-O-Tapu Thermal Wonderland, Rotorua, North Is...

John Cancalosi / Silver with Cobalt Arsenic, Cobalt, Ontario, Canada

Steven David Miller / Devil's bath crater filled with arsenic rich water, Wai-O-Tapu, Rotorua, North Island, New Zealand

Tui De Roy / Champagne Pool, a volcanic lake has constant 74 degree Celsius water including minerals gold, silver mercury, sulphur, and arsenic, Waiotapu, Rotorua, New Zealand

Tui De Roy / Arsenic-laden Laguna Verde at 4,400 meters elevation with 5,868 meter Licancabur Volcano in background, Eduardo Avaroa Faunistic Reserve, altiplano, Bolivia

Tui De Roy / Arsenic-laden Laguna Verde at 4,400 meters elevation with 5,868 meter Licancabur Volcano in background, Eduardo Avaroa Faunistic Reserve, altiplano, Bolivia

John Cancalosi / Orpiment, an ore of arsenic. Sample from Shimen Mine, Hunan, China.

John Cancalosi / Arsenopyrite (FeAsS, Iron sulpharsenide), an ore of arsenic. Hunan, China

John Cancalosi / Realgar crystals [AsS / Arsenic sulfide (red)] on Orpiment [As2S3 / Arsenic tri sulfide (yellow)] from the Palomo mine, Huancavelica, Peru, Both are ores of arsenic

Colin Monteath / Rain storm approaches Champagne Pool, volcanic lake has constant 74 degree Celsius water including minerals gold, silver mercury, sulphur, and arsenic, Wai-O-Tapu Thermal Wonderland, Rotorua, North Is...

Tui De Roy / Volcanic lake, champagne pool, constant 74 degrees Celsius, carbon dioxide fizz, minerals include gold, silver, mercury, sulfur, arsenic, thallium and antimony, Champagne Pool, Waiotapu, Rotorua, New...