This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Turmalin . Mineral tourmaline chemical composition silicate with variable composition from collection of National Museum Prague Czech Republic originally from Moravia Minerl turmaln cs ze sbrek Nrodnho muzea Praze pvodem Moravy own Karelj Tourmaline Schorl Handstones Geological and mineralogical Exhibition NM Prague