Black River Agate set in cast Sterling Silver. Black River agate is a naturally water-worn, banded agate sourced primarily from the Entre Ríos Province in Argentina. Prized by collectors, it typically features beautiful, shifting layers of cream, beige, brown, and sometimes blue or subtle black, and is often sold as cut-and-polished specimens or rough nodules.
Appearance: Features prominent fortification banding with earthy tones.
Origin: Though found in the rivers of Argentina, geologists believe they originated in Brazil and were deposited by ancient flooding.
Sizes: Can range from small, pocket-sized palm stones to massive 300-pound nodules.
Uses: Highly sought after for mineral collections, wire wrapping, and lapidary cutting/tumbling
Agates from Argentina are celebrated globally for their brilliant natural colors, intricate banding, and stunning “fortification” patterns.