A Geoscience Digital Image Library

TitleOpal (precious)
DescriptionOpal has been a popular gem for many centuries and has a very interesting structure. Opal is considered a mineraloid because this structure is not truly crystalline. The chemistry of Opal is primarily SiO2 with 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.
LocationMexico. Near Durango.
PhotographerDarla Sondrol. 2002-03-22.
CollectionWard’s Classroom Collection of Gem Minerals #10.
Key wordsopal, Mexico
Tech details222 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens.
GeoDIL number2525