Authentic and very large Agate Basin made out of an awesome patinated Burlington Chert. This piece was found in Osage County, Missouri. Stunning example of transitional Paleo artistry. This piece is ex- Mark Carter Collection. A true gem and at least a G 9.5- G 10 when Graded. 5 9/16 inches in length. Please ask any questions you may have before making an offer and feel free to ask for more photos if you need to see other angles. Good Luck to All. The item “Big Agate Basin found in Osage Co. Missouri made of Patinated Burlington Chert” is in sale since Tuesday, September 13, 2016. This item is in the category “Collectibles\Cultures & Ethnicities\Native American\ US\Pre-1600\Artifacts”. The seller is “topviewantiquesandco” and is located in Delhi, Ontario. This item can be shipped worldwide.