ROBERTO DE GUGLIEMO / SCIENCE PHOTO LIBRARY ROBERTO DE GUGLIEMO / SCIENCE PHOTO LIBRARY
Quartz crystals. Quartz (silicon oxide) is colourless when pure, but the presence of impurities can give a range of colours including white, pink, yellow, blue, green and smoky brown. The pure, colourless variety is known as rock crystal and is highly prized by collectors. This specimen measures 15 x 13 cm and was found in Morro do Cristal's Mine, Corinto, Brazil.
Model release not required. Property release not required.