This is the polished agate sphere. Diameter 1.9″ (47mm). Weight – 5.3oz (151 grams). Origin: Mongolia.
Some information about agate:
Agate is a cryptocrystalline variety of silica, chiefly chalcedony, characterised by its fineness of grain and brightness of color. Although agates may be found in various kinds of rock, they are classically associated with volcanic rocks and can be common in certain metamorphic rocks.
The stone was given its name by Theophrastus, a Greek philosopher and naturalist, who discovered the stone along the shore line of the river Achates in present-day Sicily, sometime between the 4th and 3rd centuries BC. Colorful agates and other chalcedonies were obtained over 3,000 years ago from the Achates River, now called Dirillo.
A very small sample of some of the many agates which are found all over the world. A hard stone, usually within the range of 7-9 on the Mohs scale agates are found in all colors of the rainbow, although green and blue are quite rare.