Unknown Sphere, 3 inches in diameter.
This is part of a parcel of preforms and cubes I purchased. Most of the lot were common Onyx that I will never work. The original materials all came from the estate of a 95 year old veteran that started his rock hounding career after being shot down in WWII. He stopped to pick up some pretty rocks he saw and thus missed interesting a German patrol. Gotta love the story whether it is true or not.
To see video of the sphere, click here or copy and paste: https://www.facebook.com/RockNSpheres/videos/395026738196019