Opal Specialist Mini Course
Opal Mining in Coober Pedy
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The history of opal mining in Australia is one of danger, regeneration, and success against great odds. As far back as 4,000 BCE, humans have treasured opals and mined them in various locations, such as Kenya and Hungary. However, due to an unlikely combination of geology, fortuitous finds, and the two world wars, Australia has become the world's primary source of opal since the 1880s. In the process, a rich opal-mining culture has risen around its mining fields.
Australia produces roughly 95% of the world's precious opal, including black opal. This most valuable variety is found at Lightning Ridge, the largest producer of opal by value. However, the town of Coober Pedy is the largest producer by mass. Coober Pedy's culture is so rooted in opal mining that a mining truck is raised on poles above its town sign.
The Beginnings of Opal Mining in Coober Pedy
Around 1915, a teenage boy whose father was gold prospecting discovered opal in Coober Pedy. Although the first opal claim was staked soon after, it took time before opal mining took off in the area. After WWI, returning soldiers, accustomed to living in trenches, drifted to the opal fields to seek their fortune. After WWII, a wave of Europeans left their war-torn countries to take up opal mining in Australia. As a result, sixty percent of the miners living at Coober Pedy today have Southern or Eastern European ancestry. By the 1970s, the opal rush was in full swing.
The name "Coober Pedy" comes from the Aboriginal Australian kupa piti, meaning "boys' waterhole." However, another type of hole has become quite a hazard. Over the years, miners have dug over 250,000 shafts, making Coober Pedy a dangerous place for tourists to walk around carelessly.
The Underground Houses of Coober Pedy
Roughly 1,700 people live in town full-time, working at mining-related jobs. In order to avoid the punishing desert heat, many live in underground houses. Burrowed into hills, these houses require ceilings a minimum of 4 meters high to prevent collapse. Not surprisingly, many homeowners (or home diggers) have found opal while excavating.
In the past, grocery stores sold explosives, and homeowners blasted the sides of their houses to find opal. Sometimes, they even blasted into a neighbor's home. Mining in residential areas is now banned. However, many miners get around this loophole by "expanding" their houses to build additional guest rooms.
Early Mining Methods
For the most part, a small number of miners worked together on opal-mining ventures, rather than large corporations. The earliest miners dug their 3 to 10-meter shafts by hand. In order to prevent the dusty, sun-baked soil from collapsing, they reinforced the walls with timber. They lowered themselves into the shafts with windlasses, then removed the waste soil or mullock via buckets lifted by the windlasses. Miners dug tunnels the old-fashioned way, with shovels, pickaxes, and sometimes with homemade explosives buried in pockets of soil.
With any luck, miners found veins of common opal that twisted and turned throughout the rocks. They followed these veins in hopes that some might become precious opal. More often than not, the veins either disappeared or plunged into untraceable depths.
Occasionally, miners discovered the opalized fossils of prehistoric animals or plants. Over millions of years, these remains had turned into opal material.
Modern Mining Methods
Beginning in the 1970s, mechanized opal mining became prevalent. It usually involves advanced equipment such as Calweld drills for shaft digging and tunneling machines or front-end loaders for horizontal tunneling.
Automatic bucket tippers or gigantic pipe vacuums transport the mullock excavated by machine or explosives. This soil is then either transported to a drum mounted on a truck (like the one atop the Coober Pedy town sign) to be emptied later or shot out by the vacuum into a pile close to the shaft.
Supposedly, an experienced miner can tell from the sound of the vacuum when opal has been found. If miners find precious opal, they must extract it very carefully, since it can be quite fragile.
Deciding How to Mine for Opals
Mining always involves assessing investment versus payoff. Some solitary miners choose to start their enterprises small. For example, they lower themselves down abandoned mine shafts using cable cranks or rope ladders attached to their trucks.
In contrast, miners who choose to use advanced methods can dig quickly. They can also dig test shafts before committing to excavating large areas. These miners will sometimes use bulldozers to remove surface layers of dirt, while workers on the side watch for traces of opal and check opal veins for precious material. Other options include jackhammers and dynamite.
Of course, the more advanced the method, the higher the cost and greater the risk of damaging potential opal veins.
The Hazards of Opal Mining
Opal mining is a dangerous venture, especially for those working alone. Tunnels often don't have enough oxygen, and cave-ins may occur. Sudden storms can also flood them. Workers face extreme heat above ground and claustrophobia below ground. Furthermore, opals occur hidden in veins, pipes, or kernels within rock. Thus, miners can never tell where opal is to be found until they start digging.
The first opal discoveries in Australia were serendipitous. For example, a horse kicked up a lump of opal, or a teenager picked some sparkly stones off the ground. Miners then dug close to these locations. Of the opal found today, 95% is worthless gray, white potch, or common opal without phenomenal properties like play of color.
Personalities and Dreams
Australia's opal fields abound with stories of spectacular finds and eccentric characters. Many miners left their past lives to seek peace (and opals) in Coober Pedy's stark terrain. Some had hectic professional careers. Others had a head start on eccentricity. For example, the colorful home of "Crocodile Harry," one of Coober Pedy's must-see tourist destinations, belonged to a former crocodile hunter and self-declared Latvian baron in hiding.
Of course, here you'll also find the average miners who dream that the next foot of ground will yield an opal that will make them millionaires. For most, hoping for this jackpot keeps them underground, searching with flashlights for a gleam of color. Sometimes, they're richly rewarded.
Examples of Coober Pedy Opal
Phoebe Shang, GG
A gem lover and writer, Phoebe holds a graduate gemologist degree from the Gemological Institute of America and masters in writing from Columbia University. She got her start in gemology translating and editing Colored Stone and Mineral Highlights for a professor based in Shanghai. Whether in LA, Taipei, or New York, Phoebe spends her time searching for gems to design and being lost in good books.
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