219 unconfined samples without any preparation were tested
parallel and perpendicular to the banding. The samples were taken
directly from the slabbed core and met the critical sample volume of
480 cm3 according to ISRM (2006). Due to the uneven surface of the
samples perpendicular to the banding the SSRH was often measured
as zero (0) and therefore excluded as not reliable. Hence the SSRH
results measured perpendicular to the banding were not further
considered in this study.
Additionally, 70 samples were cut in order to fit 30 50 mm2
moulds, embedded into epoxy and dried for 24 h. Afterwards these
samples were ground and final polished to 0.04 μm to obtain a flat
mirror surface for petrographic analysis. This study opportunistically
tested these blocks, but due to the preparation these confined
samples were only tested parallel to the banding. Although the
critical volume of the prepared samples did not meet the specifications according to ISRM (2006), all samples were prepared and tested
equally. As the objective was to illustrate the effect of type and rank
on hardness, these results were comparable and fit for purpose.