Opal Mining

We have been mining for over 36 years. This is our D9H Caterpillar bulldozer. This is Andrews toy, Andrew is 71 years old and still mining today. He uses the bulldozer to open cut our claim down to about 15ft. We are looking for a level where the opal generaly occurs at. This bulldozer runs at approx 50 litres per hour.

This a Calweld drilling rig. The machine is like a big post-hole digger, once the bucket fills up it has to be brought up and emptied. Maximum depth varies a little but its about 90 feet, or 30m. Coober Pedy is pitted with many thousands of abandoned shafts

The machine on the left is whats known as a blower, It is like a large vacuum cleaner. The blower is attached to a small tractor with a rotating cutting head on it, a tunneling machine (pic coming soon). The image on the right is the blower pipe in the shaft, This particular shaft is about 80 feet deep.

The left image is what it looks like underground in a mine, Two miners on a break while the third is drilling holes in the wall, 10m to the right of camera, for shots (bombs) to be set. This place was mined with a round tunneling machine, thats why the walls are curved. It's about 5ft high so walking has to be done hunched over(If you're tall). The lengths of tunnels are called drives.

The right image is what a square drive would look like. Sort of... This drive has been flooded, the moisture can still be seen in the walls. Normally it would be approx 6ft high, Easier to walk through! This one is half full of drying mud. The mud is about waist deep.

Danger signs are common around Coober Pedy, they are not there for amusement. There is an uncountable amount of mining shafts in the Coober Pedy opal fields. No one backfills their shafts and not all mining shafts can be seen until your standing next to them.

The official word is as follows:

Advice to people who wish to enter the Coober Pedy Proclaimed Precious Stone Field.
The field is Crown land and under the control of the Minister for mines and Energy. A person entering a Precious Stones Claim (PSC) without the claim owners permission commits an act of trespass and may be subject to a penalty of up to $1,000. Access to the prescribed precious stones field at Coober Pedy may be dangerous due to the existence of deep shafts. Consequently, access has been restricted and fencing and hazard identification and safety signs erected.
To enter may make you personally liable for any injury incurred whilst on the field.

Any miner with a mining permit can peg a claim of 50m x 50m or 50m x 100m in which ever area they like as long as it is outside the town. A partnership can be formed between any number of miners but usually it's between three or four trusted people. First a prospecting shaft can be drilled into the earth with a Calweld drill. This drill can dig a maximum depth of 100 feet, as the bucket is emptied it is searched through. Tunnelling machines, with their revolving cutting heads, are used to dig through the ground and can tunnel at about 12ft (4m) per hour. Considering it used to be done by hand with pick and shovel technology has gone a long way for miners. Bulldozers move dirt to make an open cut and show where the level is and any seam of opal is worked by handpicks to remove it. Any opal found is divided up between the partners according to what they have decided, usually the person which owns the machinery being used gets the largest percentage.

When opal is found it is not always large pieces of rock with brilliant colours running all the way through it. In most cases the opal is found in smaller pieces with a bar of colour running through potch (opal without colour) or sand stone. Once the opal is cleaned by putting it into a water filled tumbler or cement mixer which cleans about 95% of the dirt off the rock, any dirt which remains it cleaned by hand with a pair of strong pliers.

In order to sell rough opal it is necessary to class it by separating the better pieces from the lower grades of opal. Each grade is put into its own bag. The price of rough opal is determined by the partnership according to how much they believe their opal is realistically worth. This rough opal is measured in ounces and priced accordingly, for example the best bag equalling 3 ounces of their parcel may be $2000 an ounce. Now whether they receive their asking price from opal buyers is a different story.

Noodling

Noodling machines are also used by passing the rocks and dirt onto a conveyor belt under an ultra violet light to show the colour. Anybody that wants to search through the disregarded dirt and rocks bought up by the drill is free to do so. Just remember to stay away from any dumps which look like they are still being used.

Many tourists passing through Coober Pedy join a tour or find their own place and enjoy their noodling time, unfortunately it isn't always that easy.