Quartz Reef Mining
Primary gold typically happens in quartz veins. The removal of gold ore from these tough quartz veins was traditionally referred to as quartz reef mining.
A Prussian engineer, Jacob Brache was the foremost to feel that quartz reefs may have even more gold than alluvial fields.
The novel mining firms had to sink very profound shafts to get quartz from the reefs profound underground. Horizontal tunnels known as drives were dug out from the shaft at dissimilar levels to discover the gold-bearing rock.
All rock excavated out had to be hoisted to the surface. So did lots of water and even the workers at the final day. Large engines were installed to hoist lifts and buckets up the shafts.
On the float up above the shaft stands a building called the poppet head or pit head. The poppet head had a wheel known as a gin wheel which lifted buckets of rock up to an elevated platform known as a Brace. Wheeled buckets then took the rock along elevated tracks to waste dumps or processing works. The steel cable that raised the bucket passed over the gin wheel.
Prospecting for Quartz Reefs and Other Deposits
Reef prospecting entails locating gold bearing quartz veins. The majority of the accessible reefs have most likely been found by early prospectors and explorations; as a result, remote and poorly outcropping reefs are more probable to be found. These days, in the short term, this form of prospecting is not as rewarding as metal noticing.
Once a quartz reef is situated, it might be rewarding to go behind the reef along its length searching for auriferous locations. Gold concentrations may augment and lessen along the length of a quartz reef.
In areas that are badly exposed, reef prospecting is mostly limited to the low hills and rises, where outcrop is best. In intensely weathered areas, the surface expression of quartz reefs will be in the type of supergene deposits (portrayed previously). The presence of gossans is an indicator to an underlying ore body. Gossan is the weathered manufacture of an ore body and is stained a variety of colors from the oxidation of ore minerals. It normally has iron oxide minerals with a relict box work texture left at the rear after the removal of cubic pyrite. As pyrite is frequently associated with gold deposits, Gossan might point out the presence of an ore body.
The most excellent method for properly identifying sulphide minerals, mainly microcrystalline grains, is polarized light microscopy (petrography). A petrography laboratory regularly does this kind of work.