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Let's Rock => Identifications of Materials => Topic started by: Sifu on May 12, 2016, 12:45:56 PM

Title: Chert?
Post by: Sifu on May 12, 2016, 12:45:56 PM
Frost heaved out of the ground in Eastern Oregon. Fracture pattern reminds me of chert, but it doesn't seem as silicaceous (is that a word?) as other chert I've seen west of the Cascades.
Title: Re: Chert?
Post by: lithicbeads on May 12, 2016, 12:50:24 PM
I would say yes but  maybe it fits best in the sub category of flint. These are subjective categories to a degree. I have seen and cut low grade Biggs that looks like that and is low silica and Biggs is a chert, sedimentary jasper.
Title: Re: Chert?
Post by: Sifu on May 12, 2016, 12:56:13 PM
Here is a photo of a different one. I get that flint and chert are like two flavors of vanilla ice cream - maybe one is French vanilla and the other is vanilla bean? I will mess around with cutting and polishing this stuff and see what happens. Appreciate the added perspective - thanks.