The shape index relates the mass of the non-cubic
particles divided by the mass of the cubic particles times
100. Where the longest axis divided by the shortest axis is
greater than 3, the particles are considered to be non-cubic.
Since all the particles were weighed and measured with the
DB it is possible to make an estimate of the shape index. For
sample 1 it would be 10% where as for sample 2 it would be multiplied by the area based on a crude assumption. In
contrast this new method actually measures the thickness
of the particles and is thus much more accurate.
The 3-D methods by Kuo et al. [13], Frost and Lai [14],
Maerz [15] and Weingart and Prowell [16] differ from
Fernlund’s method in that they measure one particle at a