The geochemistry of agate and chalcedony in volcanic rocks represents an intricate record of silica precipitation and crystallisation processes occurring under variable thermal and chemical conditions ...

Forbes contributors publish independent expert analyses and insights. David Bressan is a geologist who covers curiosities about Earth. Chalcedony, from the Greek trade city of Kalzedon, is a variety ...

L-14 (Little Colorado River Chert/Quartzite/Petrified Wood/Chalcedony/Agate): Not direct collection from outcrop. Provenience includes samples from gravel deposits. Unknown collection procedure.

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An Antique Victorian, Gold, Chalcedony Agate and Turquoise Agate and Turquoise Brooch. Gold 3cm.

Van-hal West African School British School Baron Gilles Ghez Colin Almack Albino Galvano Thai School, 17th Century Northern European School, 18th Century Polia Pillin Artists > Agate > Artworks > An ...

IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. NMNH - Anthropology Dept.

Agatized Coral hunting is becoming one of my absolute favorite things to do... beautiful colors, geodes, bubbly botryoidal agate... what else could you ask for?! Finding a fossil/gem/mineral all in ...