Quartz reef mining is a type of

gold mining Gold mining is the extraction of gold resources by mining. Historically, mining gold from alluvial deposits used manual separation processes, such as gold panning. However, with the expansion of gold mining to ores that are not on the surface ...

in "reefs" (

veins Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated b ...

) of

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...

. Quartz is one of the most common minerals in the earth's crust, and most quartz veins do not carry gold, but those that have gold are avidly hunted by prospectors. In the shallow, oxidized zones of quartz reef deposits, the gold occurs in its metallic state, and is easily recovered with simple equipment. Quartz reef mining played an important role in 19th century gold-mining districts such as

Bendigo, Victoria Bendigo ( ) is a city in Victoria (Australia), Victoria, Australia, located in the Bendigo Valley near the geographical centre of the state and approximately north-west of Melbourne, the state capital. As of 2019, Bendigo had an urban populat ...

Central Otago Central Otago is located in the inland part of the Otago region in the South Island of New Zealand. The motto for the area is "A World of Difference". The area is dominated by mountain ranges and the upper reaches of the Clutha River and tributa ...

in New Zealand, and the California mother lode.

Mining

Mining Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic via ...

the ore usually required mine shafts sunk to mine quartz from the reefs, sometimes deep underground. Horizontal tunnels called drifts were dug out from the shaft at different levels to find the gold-bearing

rock Rock most often refers to: * Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids * Rock music, a genre of popular music Rock or Rocks may also refer to: Places United Kingdom * Rock, Caerphilly, a location in Wales ...

. All the ore was hoisted to the surface for processing. Water had to be removed by pumping. Big hoisting engines were installed to hoist lifts and buckets up the shafts. On the surface above the shaft stands a building known as the

headframe A headframe (also known as a gallows frame, winding tower, hoist frame,Ernst, Dr.-Ing. Richard (1989). ''Wörterbuch der Industriellen Technik'' (5th ed.). Wiesbaden: Oscar Brandstetter, 1989. pit frame, shafthead frame, headgear, headstock o ...

. This contained a wheel called a gin wheel which lifted buckets of rock up to a raised platform called a brace. Wheeled buckets then carried the rock along elevated tracks to waste dumps or processing works. The steel cable that hoisted the bucket passed over the gin wheel.

Processing

The gold was brought to the surface as small particles embedded in lumps of quartz. The quartz was then crushed into a fine dust by stamping batteries in a

stamp mill A stamp mill (or stamp battery or stamping mill) is a type of mill machine that crushes material by pounding rather than grinding, either for further processing or for extraction of metallic ores. Breaking material down is a type of unit operatio ...

. A stamp battery contained a row of stamps. On the bottom of each stamp was a heavy piece of iron or steel. Each battery was driven by a cam shaft which was turned by a

water wheel A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a wheel (usually constructed from wood or metal), with a number of blades or buckets ...

. The steel shoes went up and down between wooden guides and pounded the quartz which had been fed into steel boxes underneath the stampers. Ideally the stamping batteries would work 24 hours a day. After crushing, the quartz was mixed with water to make

mud A MUD (; originally multi-user dungeon, with later variants multi-user dimension and multi-user domain) is a Multiplayer video game, multiplayer Time-keeping systems in games#Real-time, real-time virtual world, usually Text-based game, text-bas ...

which then ran down sloping tables, called concentrating tables. On top of these tables were

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

sheets coated with

mercury Mercury commonly refers to: * Mercury (planet), the nearest planet to the Sun * Mercury (element), a metallic chemical element with the symbol Hg * Mercury (mythology), a Roman god Mercury or The Mercury may also refer to: Companies * Merc ...

, which amalgamates with gold. The gold particles stuck to the mercury, and could be collected from there. In more recent times, gold has been recovered by the

cyanide process Gold cyanidation (also known as the cyanide process or the MacArthur-Forrest process) is a hydrometallurgical technique for extracting gold from low-grade ore by converting the gold to a water-soluble coordination complex. It is the most commonly ...

, instead of using mercury-coated plates.

Quartz mines

Victoria Quartz mine Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

Bendigo Bendigo ( ) is a city in Victoria, Australia, located in the Bendigo Valley near the geographical centre of the state and approximately north-west of Melbourne, the state capital. As of 2019, Bendigo had an urban population of 100,991, makin ...

Victoria, Australia Victoria is a state in southeastern Australia. It is the second-smallest state with a land area of , the second most populated state (after New South Wales) with a population of over 6.5 million, and the most densely populated state in Au ...

(Its deepest shaft used to mine a quartz reef was almost a kilometre and a half deep.) * Central Deborah Gold Mine, Bendigo (The mine still stands today. Mining began in 1938, and was continuous for 16 years. It was a deep reef quartz goldmine. During the working life of the mine, 60,000

tonne The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United State ...

s of quartz was brought to the surface, yielding 1 tonne of gold. *

Gold Hill (Nevada County, California) Gold Hill in Grass Valley, California, was the site of one of the first discoveries of quartz gold in California. While quartz gold was also found in other areas of Nevada County, California during the same time, it is this find near Wolf Creek th ...

, USA (This site of one of the first discoveries of quartz gold in California, and now

California Historical Landmark A California Historical Landmark (CHL) is a building, structure, site, or place in California that has been determined to have statewide historical landmark significance. Criteria Historical significance is determined by meeting at least one of ...

No. 297: "...this discovery created the great excitement that started the development of quartz mining into a great industry."

References

{{Reflist

External links

*http://www.egold.net.au/biogs/EG00055b.htm *http://www.egold.net.au/biogs/EG00024b.htm
www.central-deborah.com/education/Project doc
Gold mining History of mining Quartz mines Underground mining