Tourmaline crystals (green) in quartz. Tourmaline is a boron-silicate mineral that forms crystals that are straight elongate prisms. It occurs in a nu

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Tourmaline crystals (green) in quartz. Tourmaline is a boron-silicate mineral that forms crystals that are straight elongate prisms. It occurs in a number of colours, some of which are much sought after as semi-precious gemstones. This specimen, from Minas Gerais, Brazil, is 25 centimetres wide.

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Size: 5616px × 3744px
Photo credit: © DIRK WIERSMA/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: -, boron, boron-silicate, crystal, crystalline, crystals, dioxide, gem, gemstone, geological, geology, mineral, mineralogy, multiple, quartz, rock, semi-precious, silicate, silicon, tourmaline, turmaline, verdelite