A Geoscience Digital Image Library

TitleSchorl with muscovite in quartzite
DescriptionSchorl belongs to the tourmaline group. It has the chemical formula of NaFe3(Al,Fe)6Si6O18(BO3)3(OH)4. Schorl, like all tourmalines, piezoelectric which means that when a crystal is heated, compressed or vibrated a different electrical charge will form at opposite ends of the crystal. Conversely if an electrical potential is applied to the crystal, it will vibrate. It is also pleochroic. This sample is approximately 5 cm.
LocationUSA ▹ South Dakota. Near Keystone.
PhotographerShannon Heinle. 2001-11-28.
CollectionUniversity of North Dakota Mineralogy Collection #1303.
Key wordsschorl, tourmaline
Tech details776 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens.
GeoDIL number1857