2.9" Polished Bird's Eye Jasper (Rhyolite) Sphere - Arizona

About Bird's Eye Jasper

Bird’s Eye Jasper is a striking orbicular stone from Arizona, known for its distinctive round “eye-like” patterns scattered across a colorful volcanic matrix. Despite its common trade name, Bird’s Eye Jasper is not a true jasper. Instead, it is an orbicular variety of rhyolite, a silica-rich volcanic rock formed from explosive volcanic activity.

Rhyolite forms when high-silica lava erupts and cools rapidly near the Earth’s surface. In certain conditions, mineral-rich fluids and variations in crystal growth during cooling create orbicular structures—concentric spherical patterns embedded within the rock. These orbicules form as minerals such as feldspar, quartz, and iron oxides crystallize outward from small nuclei in rhythmic layers. The result is a rock filled with rounded spots or “eyes,” often surrounded by subtle halos or rings.

The colors of Arizona Bird’s Eye Jasper vary widely and can include reds, purples, pinks, yellows, creams, and browns, reflecting the presence of iron oxides and other trace minerals in the volcanic material. When cut and polished, the orbicular structures become especially pronounced, giving the stone its characteristic appearance reminiscent of scattered eyes.

Most material labeled Bird’s Eye Jasper comes from rhyolite deposits in the desert regions of Arizona, where ancient volcanic flows and ash deposits have been exposed by erosion. The stone is typically collected as surface float from weathered rhyolite outcrops.