GARNET SQUARE

Mining

SURVEY AND DEMARCATION

Two kinds of deposits may be distinguished in Cuamba. The "alluvial" and "insitu" deposits. The initial prospecting is done under guidance of our geologist. An arc of garnetiferous biotite schist traverses the mining area.

MECHANIZED MINING

The alluvial deposits lend themselves readily to mechanization. The deposits are marked in a numbered grid pattern. This will enable the identification of richer deposits from visual inspections and results from washing plant recovery. The day-to-day direction of mining is controlled by a pit supervisor. There is a constant feed-back from the washing plant to the mining area to identify high quality material.

After removing the overburden garnet bearing alluvium is loaded onto dumper truck(s) and driven to the washing plant for recovery.

The deposits are marked in a numbered grid pattern. This will enable the identification of richer deposits from visual inspections and results from washing plant recovery. The day-to-day direction of mining is controlled by a pit supervisor. There is a constant feed-back from the washing plant to the mining area to identify high quality material.

RECOVERY

The recovery consists of two sections - the washing plant and the sorting office.

WASHING PLANT

The washing plant has a hopper to receive the alluvial material which is led into the scrubber and trommel to seperate sand and clay from the course material among which the garnets. The jiggs do separate the garnets from other course material

ASSORTING AND QUALITY CONTROL

The garnets are shifted to the quality control section. All garnets, starting from 0.5 grams are checked on type and their quality, each by hand using 3 different selection methods. From the bare eye with ordinary light tables (eyeclean quality) and bedsidelamps (lamp clean quality) to the use of glass fiber and magnifier for more detailed inspection and selection of fiber clean quality. As a result the exported gems reach a rejection rate of maximum 5%