Local Tour around Australia ~ NSW 14

When talking about Lightning Ridge, the first thing we need to understand is the status of black opal, a member of the opal family. The so-called "Black Opal" is named because the parent rock it grows on is black and the base color is black, which is different from other common opal types. In fact, black opal is not just black, but its base color is darker (mostly black or gray) than other opals. The production of black opal is very rare, accounting for only 5% of the total opal production in Australia. Therefore, compared with other opals, black opal is the most valuable and precious. In addition, when evaluating the value of black opal, one of the very important criteria is its iridescence effect, that is, when it is rotated under the light source, colorful spots can be seen. The bright and prominent iridescence has always been loved by the world. Among them, red has the highest value, which also includes purple, orange and other shades, but the combination of strong and bright crimson and orange with a black base is the best.

There is a special mining area application management department in Lightning Ridge. Miners who want to obtain mining rights must pay a deposit of about 1,000 Australian dollars per mine every time they apply for a new mine, and each mine is uniformly divided into 50 meters x 50 meters specifications; in addition, applicants must meet all mining standards and pass the relevant training courses offered by the management department. After passing the examination, they can apply for mining rights to the mine. Then, the mine owner needs to pay the corresponding management fees to the mining area management department every year. The local mining area management department has very strict requirements for mining area environmental protection. If one day in the future the mining area applied for by the mine owner has been fully mined, or nothing can be mined and needs to be abandoned, the mine owner must fill up all the abandoned mines - that is, all the mines visible on the surface, and all the surrounding garbage must be cleaned up, and then the management department must personally review it. In addition, relevant personnel from the management department will personally go to the mine to review the width of the mine. The normal width of a mine is 2.4 meters. If it exceeds 2.4 meters, the mine owner must fill the mine with many thick wooden piles to stabilize the internal structure to prevent the mine from collapsing again after being filled. In fact, many times, these mines are more than 2.4 meters deep, so they need to be filled with many wooden stakes to fix them before they can be abandoned.

Only when all abandoned work of the mine owner meets the standards will the mining area management department return the deposit to the mine owner. There have been cases in the past where small animals or people have accidentally fallen into mines, resulting in serious injuries or deaths, so the mine management department must strictly control any safety hazards. After all, Australia has very strict requirements on the safety performance and safety indicators of all these dangerous operations.

Looking at the small towns around Lightning Ridge, they are basically all farmland, and often a large area of farmland is planted with one crop. There are basically no people in these places, and there is only one farmer working in a large area of farmland. Throughout history, miners and farmers have had different interests, so they have each been trying to get more of their land. In recent years, the Lightning Ridge Miners Association has also been fighting for land for miners, and they have also spent a lot of money to buy land from farmers to mine opals.Generally speaking, the opal ore layer is located between 30 and 60 feet below the surface, so it is dangerous for miners to mine at this depth. This requires that miners must have a lot of relevant professional knowledge, otherwise mining accidents are likely to occur. Of course, many mining accidents have occurred here in history.

During the process of digging a mine, as the mine is exposed to the air for a long time, the moisture inside will slowly evaporate, the mine will become drier and drier, and the risk of the roof collapsing will easily occur. Therefore, miners have to constantly use wooden stakes to support the excavated areas during the process of digging the mine, so that the entire mine can be stable. If the mine is narrowIf the mine is narrow, like a tunnel, then stakes are not needed. Usually, miners use small excavators to dig their mines. After the small excavators dig out the soil, they have to transport all the soil to the ground and send it to a special place by truck for cleaning. It takes many days to clean a truckload of soil each time. Only after the soil is cleaned can people find out whether there are opals in it.