Pica glass, or Atacama desert glass, is impact glass found along a broad 75.6 kilometer stretch of the Atacama Desert in northern Chile, near the town of Pica. Pica glass is notably light weight containing many folds, twists and flow lines. [1] Pieces are be up to 50 centimeters across. [2]
The glass likely originated when a comet entered Earth's atmosphere and exploded over the Atacama desert in the Late Pleistocene age sometime between 14,000 and 12,000 years ago. This explosion occurred soon after the arrival of people in South America so it was likely witnessed by some early hunter-gatherers in the area. [1] [2]