Mining of the ruby mineralisation by Gemfields has been primarily focussed on three main clusters of production pits in separate areas, termed by Gemfields as Mugloto (the western portion of the deposit), Maninge Nice (the north-eastern portion of the deposit) and Glass (the south-eastern portion of the deposit).

The Montepuez ruby deposit is hosted by the Montepuez Complex, a strongly ductile-deformed, wedge-shaped, metamorphic terrane. The Montepuez Complex is composed of orthogneisses ranging from granitic to amphibolitic in composition, and para gneisses comprising quartzite, meta-arkose, marble lenses, quartz-feldspar gneiss, and biotite gneiss. These metamorphosed sedimentary rocks have been intruded by granite, granodiorite, and tonalite.

Intense deformation has resulted in a highly complex structural framework, with the local units folded into tight and isoclinal folds dissected by a suite of mainly northeast to southwest trending shear zones.

The Montepuez Complex is bounded by thrust faults to the north by the Nairoto Complex, the oldest rocks in the region composed of ductile-deformed metamorphosed intrusives, and to the west by volcano-sedimentary meta-suites of the Xixano Complex.

Ruby and corundum mineralisation is found in two styles: primary amphibolite, and a secondary gravel bed. The main source of rubies and corundum is secondary mineralisation, although mining has also occurred from the primary mineralisation. T ........

Mining is carried out at the Mugloto, Maninge Nice and Glass areas as a conventional open-pit gravel operation with excavators, loaders, and trucks. All material is ‘free dig’ with some of the harder laterite needing to be ripped by a bulldozer. all equipment is owned and operated by the mine. Mining operations working shift schedule now have been adopted from 3 x 8-hour shift to 2 x 12-hour shift, since August 2022.

The Maninge Nice blocks target primary amphibolite and secondary gravel bed mineralisation, whereas the Mugloto and Glass areas contain only secondary gravel bed mineralisation.

Mining in Mugloto and Maninge Nice varies in depth between 5 m and 8 m. Waste mining is undertaken in 2.5 m flitches. The flitch heights are reduced as the excavation approaches the gravel bed horizon, as directed by site geologists. Small equipment sizes allow for highly selective mining. Complete extraction of the gravel is ensured by mining a minimum thickness of 1.5 m.

Grade control is constrained to visual inspection and mining of the mineralised zones is only undertaken during daylight hours. Geologists on site direct the mechanical loader from within the pit area to ensure that the gravel bed is mined correctly.

MRM recovers gemstones from a series of shallow pits at Mugloto, Glass and Maninge Nice.

MRM has included an ore stockpiling strategy to manage the expected variability in the gemstone grading distribution as well as th ........

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