Ovoidal- and mottled-textured rock and associated silica veinlets and their formation by high-temperature outgassing of subjacent magma


Ovoidal (or gusano) texture is characterized by ovoids of hydrous aluminum silicate/
sulfate minerals such as pyrophyllite and alunite associated with variable
amounts of pyrite and enargite or covellite set in a typically fine-grained matrix of
quartz or chalcedony. Inmottled (or patchy) texture the aluminum silicate/sulfate and
silica portions are irregularly intermixed. There is a continuum between ovoidal and
mottled textures.

SKU: 2010-42 Category:

Additional information


Primary Author

Donald Noble




Deposit Type

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