Microscopy of Grains of Quartz and Silica - 2015

Mining & Minerals - Evaluations / Mineral Exploration Activities - General

Chapter 1 of text: Petrology of Sandstones and Associated Rocks by Dana S. Ulmer-Scholle; Peter A. Scholle; Juergen Schieber; and Robert J. Raine in AAPG MEMOIR 109: A Color Guide to the Petrography of Sandstones, Siltstones, Shales and Associated Rocks
DOI: https://doi.org/10.1306/M1091304 

Quartz (SiO₂) is the most abundant mineral in terrigenous sedimentary rocks and is exceedingly durable (surviving multiple generations of weathering and deposition). Quartz and silica occur in many varieties—true quartz in the form of megaquartz, chert, microquartz, or chalcedony and various other forms of
silica, mainly opal (opal-A and opal-CT [cristobalite]).