geodil.jpg

A Geoscience Digital Image Library

413.jpg
TitleObsidian from Lake County, Oregon
DescriptionObsidian, volcanic glass, generally has a jet black color, but this sample is brown due to the presence of oxidized iron. Obsidian forms when magma cools so quickly that mineral crystals cannot form. This sample is 8 cm across.
LocationUSA ▹ Oregon ▹ Lake
PhotographerMike Davis. 2001-04-26.
CollectionWard’s University Rock Collection #105.
Key wordsobsidian, Oregon
Tech details364 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera, 60mm AF Nikon micro lens.
GeoDIL number413