A Geoscience Digital Image Library

TitleOpal, cabachon
DescriptionOpal, SiO2-nH2O (hydrated silicon dioxide), is considered a mineraloid because this structure is not truly crystalline. The chemistry of opal is primarily SiO2 and varying amounts of water from 5%-10% and greater. This water can help geologists determine the temperature of the host rock at the time the opal formed.
PhotographerDarla Sondrol. 2001-11-09.
CollectionWard’s Natural Science, 49 E 6208.
Key wordsopal
Tech details55 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens.
GeoDIL number1791