Quartz reefs are veins of quartz in the ground, sometimes gold-bearing.
These can be marked on maps as reef, line of reef, quartz, quartz reef, and auriferous quartz reef.
Auriferous means that the reef contains gold – but not all gold bearing reefs are marked on maps as being auriferous. Usually they are just marked as reefs, and are typically shown by straight lines.
You will also see some reefs marked as ‘outcrops’, which means that the reef is exposed at the surface, rather than lying hidden underground.
Some are also marked as “Quartz blows”. These are huge masses of quartz which have been exposed at the surface by erosion of the surrounding rock. There is an incredible example of this at Lillicur, at the Quartz Mountain Geological Reserve.
Gold can either be mined directly from the reef, by crushing the quartz and processing for gold, or from nearby areas where the gold has been eroded away from the reef over time.
This latter form of mining is called ‘alluvial mining’.