Tourmaline crystals in quartzite. Close-up of tourmaline crystals (pink) embedded in a quartzite host rock. Tourmaline has a very complex and variable composition. Clear and pure crystals of green and red tourmaline are highly prized gemstones. Quartzite is a hard metamorphic rock that originates from sandstone that has been heated and compressed,usually during tectonic compression. This sample is from San Diego,California,USA | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Wiersma, Dirk |
Bildgröße: | 5315 px × 3543 px |
Modell-Rechte: | nicht erforderlich |
Restrictions: | - |