Gold is melted at a high temperature and poured into molds. ©Getty Images

Gold is melted at a high temperature and poured into molds. ©Getty Images

Gold is a soft, yellow precious metal. It is one of the few metals that is yellow in colour.

The properties of gold

It can be melted and poured into molds.

It is malleable, which means it can be hammered or pressed without breaking or cracking.

It can be stretched into a thin sheet or into wire.

It also conducts electricity. 

It has been valued for centuries, long before recorded history.

Gold is found as nuggets or grains in rocks, or washed down in river beds mixed with the sand.  Grains of gold found in river beds is called alluvial (say uh-loo-vee-ul) gold. A deposit of gold is where there is a mass of gold in the same area.

Gold rushes

In 1851, during the time that there was a gold rush in California USA, a gold rush began in Australia. The gold in California was mainly in the form of very fine grains, called gold dust.  However, in Australia, it was not unusual for gold nuggets, some very large, to be found. The largest Australian nugget, and the largest ever found,  is Holtermann's Nugget,  weighing 286 kg and measuring 1.5 metres in length.  Nuggets that are also famous are: The Hand of Faith (27.2 kg), the Welcome Stranger (73.4 kg) and the Welcome (69.9kg).

A gold nugget. ©Getty Images

A gold nugget. ©Getty Images

How gold was mined in the Australian gold rush

A gold licence in Victoria ©Getty Images

During the gold rush, in order to search for gold, people had to have a claim and a licence to look for gold.  A claim was a area of land 3.6 metres square. Often two or three people would work a claim together, sharing the costs of licence and equipment, and sharing whatever gold they found. To keep the claim, the miner had to work on it each day, except Sunday when no mining was allowed. A licence cost 30 shillings a month and allowed the miner to keep gold from the claim. The licence fee had to be paid in order to keep the claim, even if no gold had been found that month.

Panning for gold ©Getty Imagaes

Panning for gold ©Getty Imagaes

Panning for gold

At first people looked for alluvial gold, which is gold lying in streams just under the surface of the bottom of the stream. Gold is about six times heavier than sand so it goes to the bottom of the stream or creek.  People washed creek sand in iron pans. As the dirt washed away, any gold was left in the pan because its weight kept it from washing away along with the dirt.  Alluvial gold soon ran out because so many miners were in the goldfields.

Lead mining

Underground mine ©Getty Images

Underground mine ©Getty Images

New technology developed as miners began to go deeper underground in search of gold. Another kind of gold mining was called deep lead (say leed) mining.  Underground gold deposits were called 'deep leads'. To dig underground, men dug holes called shafts about one metre square. They propped up the shafts with timber to stop them collapsing.  

A drive coming out of a shaft. ©Getty Images

A drive coming out of a shaft. ©Getty Images

At various depths they dug tunnels coming out from the downward shaft in order to look for leads.  These tunnels were called drives. One man would work down in the shaft, shovelling dirt into a bucket, which was hoisted up by a second man. The buckets were hauled up using a windlass, which wound the rope around a log as the man turned a handle. 

Any dirt containing gold was called washing stuff because it had to be washed to separate the gold from the dirt.

Miners using a sluice. ©Getty Images

Miners using a sluice. ©Getty Images

Sluicing (foreground). Note the whip in the back ground. ©Getty Images

Sluicing (foreground). Note the whip in the back ground. ©Getty Images

Separating the gold from the dirt was done in a washing cradle or a sluice box. The cradle had a metal sieve to separate larger rocks. It had wooden strips called riffles at the bottom.  As the cradle was rocked,  water was poured in to wash away the dirt. Particles of gold were left behind in the riffles. A sluice (say sloose) was a runway made of wood to let water flow downhill. It became steeper, and had riffles in the end to catch the gold left behind after the dirt was washed away.

When shafts got over 40 metres deep the windlass was replaced by a whip or a whim. The whip was a long pole pivoted on a forked stick The miner pulled on the rope at one end of the pole, which raised the bucket out of the shaft. Another version of the whip was to use a horse to pull the the rope to raise the bucket. The whim was necessary for shafts deeper than 80 metres, and cost a lot of money. A large drum had a cable running over pulleys and down the shaft, with a bucket at each end. A horse walked around making the drum revolve, and as this happened, one bucket would come up and the other would go down into the shaft.

Deeper shafts would fill with water, and had to be pumped day and night to stop the mine from flooding. Another problem with a deep shaft was that the air got bad. A windsail was used to get clean air into the shaft. It looked like the sail of a ship and worked with a scooping action, being turned to face the wind and funnelling air into a canvas tube and into the shaft.

gold in quartz rock. ©Getty Images

gold in quartz rock. ©Getty Images

After 1854 the laws changed so that big claims could be worked by groups who could join together and share costs so that they could use more advanced equipment.

Reef mining

A third kind of gold mining was reef mining. Layers, called reefs, of quartz rock containing gold are found deep in the earth. Quartz is a hard, white rock. Deep shafts and drives had to be dug, and all the rock dug out had to be hoisted to the surface. Big engines hoisted lifts for the miners and buckets of gold from the shafts. A structure called a poppet head was built at the top of the shaft. A big wheel, called a gin wheel, at the top of the poppet head wound steel cable to hoist the buckets in and out of the shaft. Gold contained in quartz rock had to be taken to a battery where the rock could be crushed to release the gold. Rock was shovelled into the stamper box, and a steam engine moved the heavy stampers to fall and crush the rock. Water moved the debris and gold was left behind.

A cradle and pan. ©Getty Images

A cradle and pan. ©Getty Images

At the Ballarat goldfields, the diggings were deserted at the end of 1851 because there was easier digging elsewhere in Victoria. However, experienced coal and tin miners from Wales, Cornwall and Scotland arrived in Australia, and they knew how to operate deep mine shafts, and so a second gold rush started in Ballarat.

Click here to find out how to pan for gold

Today gold is still valuable, but how it is mined is very different from the way it was in the 1850s!
Watch a video here.

http://www.abc.net.au/btn/story/s2823680.htm