Sudip,

the Hinckley index measures a ratio of peaks in the 02 band of the random powder XRD patterns of kaolinites. It's often called a 'crystallinity index', so considered to be a measure of how ordered vs disorderred a kaolinite sample is. But it is now known that it is more directly related to the proprortion of more or less defective types of kaolinite in a given sample. The attached reference by Plancon will give you much more detail.

sincerely,

steve

Thanks Dr S. Hillier Sir for your kind response.It helped me. I will go through the paper.

Sincerely,

Sudip