Oregon opal - forms in thunder eggs which themselves are created by when ash and mud under water (again, in this case an ocean) form and begin to rise but get trapped, then harden, creating a void beneath the ground. These bubbles create air pockets that can serve as a crucible for whatever flows in. In the case of opals, highly filtered water and silica and other trace elements flow in and under the immense heat and pressure hardens into glass. Sometimes the molecules harden in small sheet arrangements at different angles which causes the phenomenon of “fire” or “play of color” that is characteristic of opals.

Stones mined from family-owned mine in the Northwest.

Measures approximately 2 3/4" x 2"