Abstract
Comparative study of illite crystallinity calibrated to Kübler and CIS scales, done in the present paper, shows that there are differences in the limiting values of the anchizone for both scales. Adoption of the CIS scale to calibrate illite crystallinity determinations requires a re-definition of anchizone limits that would become 0.59 and 0.33º ∆2θ CuKα when using CIS scale.