[The comminution of fibrous and prismatic tremolites: the effect on the diffractometric response].

(Comminution of tremolite fibres contained in acid-washed dolomite and talc: correlation between the comminution degree and the diffractometric response). - The aim of the present work is to study the comminution of tremolite contained in an acid-washed dolomite sample and in a New York talc sample using a gentle, wet, comminution technique. Tremolite in acid-washed dolomite shows a fibrous habit of a length/ diameter ratio greater than 10/1; on the contrary, tremolite particles in the New York talc have a quite acicular or prismatic habit of a length/diameter ratio in general less than 3/1. For both tremolite types, the diffractometric responses follow trends similar and are well correlated to the comminution degree. Results confirm that the comminution of amphibolic asbestos is a crucial step for the quantitative determination of this substance by electronic or light microscopy and X-ray diffractometry.