- Johrde, L.G. and Cocks, F.H., Microhardness studies of renal calculi,
Mater. Lett. (Netherlands), vol. 3 no. 3
pp. 111 - 14 [0167-577X(85)90009-6] .
(last updated on 2007/04/10)
The development of acoustic and other methods of kidney stone fragmentation has given importance to the study of the mechanical properties of such stones. Renal calculi based upon calcium oxalate, calcium phosphate, uric acid, cystine, and magnesium ammonium phosphate have been studied using Knoop microhardness indentation methods. The microhardness of dry stones was found to vary with the calculi chemical composition, yet remained consistent within composition groups. The hardest calculi were found to be calcium oxalates with a Knoop microhardness of 68-88 kg/mm2. Other compositions have hardness of up to a factor of two lower than this