Agate — specimen 0371, photo © NMNHS
USA, Montana, Yellowstone River
Weight: 2.57 ct; size: 13.78 | 7.38 | 3.36 mm; shape: marquise; colour: dark reddish orange; clarity: translucent; cut: very good; treatment: none.
Clean specimen; very good cabochon style cut.
More information from ‘Classification’
A variety of chalcedony with layered structure.