Some larger #schorl #tourmaline crystals I managed to find inside some #luxullianite. Tourmaline is recognisable by it's long prismatic 'habit', the crystals also have a tendency to change colour along their length. Big ones are valuable as gemstones and apparently they might have been used as navigational aids for #Vikings (used to detect the sun's position pre-dawn or in cloudy conditions).

Some larger #schorl #tourmaline crystals I managed to find inside some #luxullianite. Tourmaline is recognisable by it's long prismatic 'habit', the crystals also have a tendency to change colour along their length. Big ones are valuable as gemstones and apparently they might have been used as navigational aids for Vikings (used to detect the sun's position pre-dawn or in cloudy conditions).

Mais comme je le racontais, ce sont les #schorl (tourmalines noires) les plus répandues... Comme dans les pegmatites de Beauchaud par exemple (photo M. Gonzales) #Cailloux #Minerals https://mamot.fr/media/9_iYIS5faGPLGUcFRhk