The Formation & Mining of Coober Pedy Opal
FGA Diploma in Gemmology Research Project
By Carmen Hui (FGA) 30/12/2017
The purpose of this project is to investigate the formation and mining of Coober Pedy opal.
Do you know why precious opal can be found in the central Australia and in a few other places on Earth? There are around 96% of the world’s gem quality opals originated in Australian mines. Opal is the national gemstone of Australia and was found in Coober Pedy in 1915. After that, Coober Pedy has been supplying most of the world’s gem quality opals. There are more than seventy opal fields and Coober Pedy is the largest opal mining area in the world.
Methods of Investigation
Today, the tourism industry is as important as the opal mining industry to Coober Pedy in order to provide the community with employment and sustainability. There are opal museums and opal retail shops for the public, which provide a brilliant opportunity for us to know more about opals.
As I am an opal lover, I simply cannot miss this beautiful place. Last year, I traveled to Coober Pedy and the inspiring trip widened my horizon about opal.
In the first part of the article, the structure of opal and play of colour are introduced. These also show the relationship with the quality of opal. Besides, The geological origin and geological occurrence of the material will also be described, which helps one to identify the types of opal found in Coober Pedy. I have also visited the opal factory in order to know the cutting of opal rough. By using scanning electron microscope, the micro-to nano structure of opal and its optical effect can be examined.
In the second part of the article, the opal mining history in Coober Pedy is introduced. The opal levels and the steps of mining will also be discussed. Today the number of miners in Coober Pedy is much less than that 20 years ago. The life and habits of miners also changed drastically. I have interviewed with some miners, buyer and retail owners in order to understand their perspectives on the opal mining and gain foresights on the industry.
Formation of Opal
Mining of Coober Pedy Opal