Sun, In shale matrix
Beautiful "pyrite sun" crystals in a black shale rock, taken from the coal mines in Illinois. The specimens are getting more and more rare as more of the mines are closing down. Also called Pyrite Dollar. At first glance the pyrite crystals appear to be pyrite fossils of some sort but they are an aggregate of tiny pyrite crystals. These pyrite crystals are between 3" and 4" in diameter and most are around 1/4" think. Unusual, thin flat pyrite crystals. If you were to hold one of the pyrite crystals in your hand, one face up, and turn it slightly, you notice the play of light reflecting from the lines of crystals from the center to the outer edges. Hardness 6 to 6-1/2.
The pyrite sun crystals form in the seam between the dense shale rock and the layer of coal in the coal mines and collected by the miners. The pyrite sun crystals are thought to have formed sometime around 300,000,000 years ago. Holding something this old in my hand fascinate me! I want to say "wow"!!
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite.
Pyrite normally forms in cubic crystal formations.
Item Number: M4803
Temporarily Out of Stock