Origin: Oregon, USA

Description: Mined in the high dessert, this site is only open to rockhounds about once a year. The stone comes from an ancient heritage site. Arrow heads used to be made from the stone and any stone found with red in it is an artifact.
The red occurred when the natives heated the large 8' high agate seam. This was done by digging out the softer stone underneath it and making fire pits below. When the rock was hot, the natives poured water on it from above, shattering and cracking it- much like putting a hot glass pot lid under cold tap water. The stone became easier to remove and "mine".
It was then used to make arrow heads and other ancestral tools. 
Of course, most people know it today because of it's polka dot inclusions

Chemical Composition: SiO2

Grade: Semi Precious
Appearance: Translucent/ Opaque
Inclusions: The stone is very stable and hard. There is some matrix, but not a lot. the colours range all over the place and even the browns of the polka dot are as hard as the rest of the agate, making this a great stone for cabbing.

Cost per Gram: $0.12
Size approximately 1 pc: 13cm x 7cm x 7cm
Weight approximately 1 pc: 850g

Rough is rough. We do our best to grade and describe pieces in the lot, but ultimately, they all differ.