Mining of Gemstones – The Entire Process

While gemstones are known for their extreme beauty and considerable spiritual and ornamental values, the process that goes behind the discovery of these rare minerals is equally fascinating. To truly appreciate the value of a gemstone, it is important to understand this process in detail.

Before a gemstone is ready to be sold in the market, it must first be excavated and then refined. Let us look into the details of how the mining process goes.

Excavating Gemstones

Gemstones are found deep inside the Earth’s surface, formed under great pressure and heat in a process known as ‘metamorphism’. Therefore, these naturally-forming minerals must be excavated from inside the Earth’s body through different mining processes.

There are four different kinds of mining processes, which are used depending on the topography of the mining area and the gemstones sought by the excavator. Different mining processes also require varying levels of skilled miners, and therefore, the correct process must be chosen.

Open Pit Mining

Open-pit mining is the simplest mining method that exists and is used to extract gemstones and metal ores from an open-air pit. This process is known by different names, such as open cast mining, mega-mining, and open-cut mining. This process is extensively used in countries like Russia, Chile, South Africa, Indonesia, Myanmar, the USA, Brazil, and many other places.

In this process, rocks and minerals are removed from an open-air pit, which is known as the ‘borrow’. These rocks are then washed off with high-pressure water jets, which then reveals the underlying gemstone.

However, open pit mining also has its negatives. This process creates significant amounts of waste materials and air pollutants.

Underground Mining

Underground mining, as the name suggests, involves digging a tunnel inside the Earth surface to excavate gemstones and valuable minerals. Mines can be dug as deep as 12,000 feet, and the mines can be entered through vertical or horizontal tunnels which are called adit, shaft or decline.

This process is employed when the gemstones lie deep within the surface and can not be accessed through an open pit. Expensive gemstones like emeralds are dug from underground mines. This process is very economical in terms of waste production; however, it can also be dangerous for the miners’ safety.

Digging in Water Bodies

Water bodies may not seem like the ideal gemstone mining place, but they contain several gemstones like opal, ruby, amethyst, garnet, jasper, and more.

When a water body is identified as an area suitable for mining, the miners fill large pans with water from the area. These pans are then shaken back and forth, which captures the gemstones inside the pan.

Several water bodies, especially rivers, are used as mining areas around the world.

Sea Mining

This mining process is comparatively newer than the other land-based processes. As human beings are exhausting the gemstones and minerals that are found inland, they are looking towards the seas and oceans in the quest for finding valuable gemstones.

Since the 1960s, a company called De Beers has been mining diamonds in the shallow waters off the coasts of southwest Africa. Following suit, many more mining companies are now looking to mine diamonds in the oceans.

This process, which involves using a hydraulic suction system or a continuous line bucket system, is usually used to recover pearls and ambers, but now is being considered for mining diamonds, gold, copper, zinc, silver, and more.

However, sea mining carries considerable environmental concerns, including destroying the ocean’s ecosystem and impacting the marine wildlife and the communities depending on it.

Refining Gemstones

Just excavating the gemstones is not enough, though. After excavation, the gemstones are then refined through various chemical procedures, to make them suitable for being used in jewellery and ornaments.

Chemical treatments such as bleaching, surface coating, dyeing, fracture or cavity filling, heat treatment, HPHT (High Pressure, High Temperature) Treatment, impregnation, irradiation, laser drilling, and lattice diffusion are used to change the colour, texture and structure of natural gemstones.

While gemstone refinement is a standard market practice, it is vital to disclose the treatments that a particular stone has gone through to the customers to maintain transparency.