How is gold jewellery made, and where does gold come from?
- theleehb
- Jun 1, 2024
- 3 min read
As you shop for gold jewellery for yourself or for your loved ones, or for wedding, have you ever wondered how it was made? Let us explore the fascinating journey of how gold is being mined, to being refined and crafted into jewellery.
First, gold is mined in various places around the world. The countries with the most gold produced include China, Australia, Russia, Canada, USA, Kazakhstan, Mexico, Indonesia, South Africa and Uzbekistan. Most of the gold mines are operated by large multinational mining companies.
Second, the gold ores are processed to create gold bars. Once mined, the ore undergoes crushing and grinding to break it down into smaller particles. This step prepares the ore for further processing. Since the 20th century, the primary method for gold extraction has been cyanide leaching. In this process, the crushed ore is mixed with a cyanide solution, which dissolves the gold. The gold-cyanide complex is then separated from other minerals.
Gold extracted often contains impurities such as zinc, copper, silver, and iron. To achieve high purity, two primary methods are commonly employed for gold purification. The Miller process is a rapid and straightforward process. Impure gold is melted, and gaseous chlorine is introduced into the liquid. The resulting chloride compounds form a separate layer on the surface of the molten gold. However, the Miller process yields gold with approximately 99.5% purity.
The Wohlwill Process achieves even higher purity (about 99.99%) through electrolysis. Impure gold is cast into an electrolyte solution containing hydrochloric acid and gold chloride. An electric current is applied, with the casting serving as the positively charged electrode (anode). Impurities either dissolve into the solution or settle as an insoluble slime at the bottom of the electrorefining tank. The gold migrates under the electric field to a negatively charged electrode called the cathode, where it is restored to a highly pure metallic state.
The resulting gold is then melted into molds to create gold bars.
Third, the gold bars are melted, molded and crafted into jewellery. In modern jewellery manufacturing, CAD software designs a wax model, which is 3D printed. Hot liquid wax is added to a mold, creating a wax version of the jewelry. The wax version is then added into a "wax tree".
Casting involves filling the mold that contains the wax tree with plaster. Then the wax is melted away, and a cavity is formed. Molten gold is then poured into the cavity, and once the gold is cooled, it forms the shape of the jewellery. The resulting gold-casted jewellery is cut from this "tree" and polished.
Fourth, gemstones are added to the gold jewellery. Bench jewellrs are highly skilled professionals invovled in sawing, soldering and polishing of jewellery. Gemstones like diamonds, rubies, sapphires, emeralds and jadeite are set onto jewellery and secured by prongs. Finally, the completed piece of jewellery is cleaned and polished again, and delivered to jewellery stores.
And there you have it! The sparkling jewellery that you see has come a long way, from mining gold to polishing and cutting gemstones, and setting the gemstones on the gold. Lots of hard work and dedication has been put in by countless professionals, so definitely the piece that you're buying is worth it! You can be assured that the jewellery that you are purchasing for your loved ones or for yourself is carefully crafted.
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