The matrix for this unusual specimen is basalt which later hosted a layer of gray chalcedony. From that layer emanated several, stalactitic forms of colorless, translucent, chalcedony, to 5.0 cm in length. Attached to the stalactites are a few doubly terminated, translucent light pink crystals of stilbite. The largest of these measures 3.0 cm across. This is a fine example of what happens in that open space in a cooling lava.