Wattle Gully Gold Mine Ugly
Mineral Matters #474
Yesterday, I posted about a video interview with a Wattle Gully Gold Mine miner.
I have three specimens from the mine, one of which is a very unusual rock type, monchiquite.
Monchiquite is a fascinating and rare type of igneous rock known as a lamprophyre. It is named after the Serra de Monchique in Portugal, where it was first identified. Monchiquite contains phenocrysts of olivine, clinopyroxene, and typically biotite or amphibole (barkevikite), set in a groundmass of glass or analcime (instead of feldspars). It may also contain nepheline or leucite. This rock is often highly altered and can exhibit a variety of textures and colours due to its mineral composition. It forms from ultrapotassic magmas and is typically found in small intrusions such as dikes, lopoliths, and laccoliths.
This particular specimen comes from the No. 12 Level (1,086 feet) of the mine. Iām not sure you can pick out the analcime in the specimen!
It is an ugly (but interesting) specimen for sure! š
Below: Monchiquite, Wattle Gully Gold Mine, Chewton, Victoria. Specimen is 50x43x25mm.
What a strange rock. But for sure interesting!