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 ...

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 ...