A Geoscience Digital Image Library

TitleSnowflake obsidian, Millard, Utah
DescriptionThis sample of black obsidian (volcanic glass) containing “snowflake” patches is from near Millard, Utah. Volcanic glass cools so quickly there is generally inusfficient time for mineral cyrstals to form. The snowflakes are places where the glass is partially crystallizing to form cristobalite, a polymorph of quartz. This specimen is 8 cm across.
LocationUSA ▹ Utah ▹ Millard
PhotographerMike Davis. 2001-04-26.
CollectionWard’s University Rock Collection #106.
Key wordsobsidian, Utah
Tech details468 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera, 60mm AF Nikon micro lens.
GeoDIL number414