This hornfels was collected from a section of contact metamorphism immediately above the dolerite of the formation from the farm Murrelfontein. It has "spots" of quartz, most likely inverted from tridymite spherulites, in a matrix of devitrified…
Rock Sample:
The sample is fine-grained, and the majority of the rock is dark grey in color. There is a 2.5x4cm white crystal formation on the upper edge of the sample. There are fractures running through the sample. There is some chemical…
Rock Sample:
The sample is metamorphic. It is green to light-green in color. There are very course grained tabular zones of metamorphism (12x4cm) and light to dark layering with non-uniform shapes and patterns. The grains are aphanitic. The…
Recently exhumed ijolite from shallow bulldozer cut.
Hand Sample: Shows traces of iron oxidation in isolated areas. Small (> 0.5 mm in diameter) nodules, with the appearance of small sand grains appear in clusters on one face of the rock (not…