Fascinated by small cleavage

If you are fascinated by small cleavage, this report brings (or did, at the time it was published) exciting news:

The resistance of diamond to abrasion,” E M Wilks and J Wilks, Journal of Physics D: Applied Physics, Volume 5 Number 10, 1972.  The authors, at the University of Oxford, report:

“These experiments are a continuation of earlier work on the resistance of diamond to abrasion whilst being polished and ground. The most striking feature of the results is the very great difference in the resistance, or abrasion hardness, observed on the various faces for different directions of abrasion. A discussion of the variations shows that grinding and polishing generally proceed by a process of cleavage, on a microscopic scale.”