| Abstract: | The variation in the microhardness of the magnesium orthosilicate crystals has been determined using Vicker's microhardness indentor. The length of the rays of dislocation rosettes around the indentation, obtained by etching the indented cleavages have been measured. It is observed that: (i) irrespective of the relative orientation of the indentor and the crystal, the median vents initiated at the sharp indentation edges, (ii) the microhardness of the crystals depends on the applied load, and (iii) the microhardness of the crystal is independent on the duration of loading. The implications are discussed. |
