The journey of a gemstone from its raw, uncut state to a finished piece of jewellery involves a complex process that requires the collaborative effort of several skilled professionals. From the miners who extract the raw material to the artisans who cut and polish the stone, and finally, to the retailers who bring the finished product to market, each step is essential in bringing these precious gems to the hands of consumers. In this article, we will take a deep-dive into the intricate journey of a gemstone and the many steps involved in transforming it from a rough mineral to a stunning piece of jewellery.
Step 1: Scouting for Mines
The world is abundant with gemstones, but some locations have become synonymous with certain types of precious stones due to the geological conditions that favour their formation. Scouting for locations to mine in often involves searching for specific geological formations that are known to host certain types of gemstones. For instance, the mines in Kashmir and Sri Lanka are well known for producing high-quality sapphires. Colombia's Muzo mine is renowned for its top-quality emeralds, while Myanmar's Mogok Valley produce some of the world's most expensive gemstones, particularly the coveted Burmese Rubies. This has led to the emergence of certain gemstone localities that play a vital role in the sourcing and distribution of gems. Geologists and experts employ various methods to locate gemstone deposits, such as geological mapping, airborne surveys, and geophysical methods, among others.
Geological mapping involves analysing and interpreting the geology of a region to identify areas with the potential for gem mineralization. This includes examining the age and composition of rocks and sediments, the structural framework of the area, and the presence of mineral deposits. Geophysical exploration involves using instruments to measure the physical properties of rocks and soils to identify anomalies that may indicate the presence of gem minerals.
Additionally, experts also use remote sensing techniques to identify potential gem mineral deposits. This includes using satellite imagery to identify geological features, such as faults and fractures, that may indicate the presence of mineralization. They also use airborne surveys, such as electromagnetic and magnetic surveys, to detect anomalies that may indicate the presence of minerals.
The famous Mogok Valley Mine in Burma (Myanmar)
Once a potential gem mineral deposit has been identified, experts use a combination of drilling, trenching, and sampling to determine the quality and quantity of the deposit. This involves taking core samples of the rocks and sediments and analysing them for the presence of gem minerals. For example, if a potential deposit is identified as containing corundum, experts may drill core samples and analyse them for the presence of rubies or sapphires. The results of these tests help determine if the deposit is viable for further exploration and potential mining.
Step 2: Gemstone Mining
After a potential gem mineral deposit has been assessed, the next step is the mining process which can range from using heavy machinery to less impactful methods with lower costs such as small-scale artisanal mining. The specific method used for mining gemstones depends on various factors, including the type of gemstone, its location, and the deposit size.
For example, in Sri Lanka, small-scale miners use hand tools to extract gems from shallow pits and alluvial deposits, employing artisanal mining. In contrast, large-scale open-cast mining is commonly used in places like Australia and Africa, where heavy machinery is used to extract gems from vast open-pit mines.
Small-scale artisanal mining in Sri Lanka (Source: GIA)
Underground mining involves excavating tunnels and shafts deep beneath the earth's surface to access hidden ore deposits. Once the gems are extracted from these deposits, they are transported to the surface through an intricate network of tunnels. Deep-sea mining is a relatively new technique that involves extracting mineral deposits from the ocean floor. Countries like Japan are exploring this method to extract precious metals and rare earth minerals from the seabed. Additionally, river digging is a common method where gemstones like Opal, Garnet, ruby and Topaz are found in rivers and streams. Artisanal miners use simple tools to extract gems from riverbeds.
Once a mine is discovered, explored, and excavated – the large rough specimens are obtained and sold in auctions to gemstone manufacturers, who further process these rough gemstone minerals.
Step 3: Gemstone Cutting
Once the rough mineral is extracted, it undergoes a process of preliminary cutting to remove unnecessary elements such as soil, dirt, and rocks and obtain a rough shape composed mostly of the gem-quality mineral. This rough gemstone mineral is then inspected for inclusions or other imperfections that may need to be removed. X-ray techniques are often employed to examine the internal structure of the gemstone for any hidden defects.
The lapidary's first step in gemstone cutting is to assess the rough for its shape, symmetry, and balance. This crucial step determines the general orientation of the gemstone and involves identifying any flaws that must be removed to achieve the desired shape and size of the finished gem. Once the stone is approved for further processing, it is cut and polished using a range of techniques like traditional hand-cutting or machine grinding to transform it into a polished gemstone.
The process of gem cutting calls for a delicate balance to be maintained between preserving the carat weight and enhancing the visual appeal of the stone. Lapidaries often face the tough decision of whether to prioritize one over the other. A larger stone with a heavier carat weight may have more inclusions, while a smaller stone with better clarity and visual appeal may cost more per carat, but would lose its size premium. Ultimately, this decision is based on market demand and the buyer's specific requirements, whilst maximising the value of the stone.
Once a plan has been developed, the next step is to create a preform. A preform is a rough shape that is close to the final shape of the gemstone. This is done using a diamond saw or grinder to cut the stone into its basic shape. The preform is then shaped using a grinding wheel to remove excess material and refine the shape. This is followed by a series of finer grinding and polishing steps to create a smooth, polished surface on the gemstone. The final steps involve checking the angles and symmetry of the gem and making any final adjustments, if required.
An Emerald being faceted
The lapidary then moves on to either faceting the gem or cutting it en cabochon - depending on the desired result. Faceting involves cutting flat, polished surfaces on the stone in a specific arrangement to maximize its brilliance and sparkle. This technique is often used for transparent or translucent gems such as diamonds, sapphires, and emeralds. On the other hand, cabochon cutting involves shaping and polishing the gemstone into a smooth, rounded, and convex top with a flat or slightly domed base. This technique is commonly used for opaque gems such as turquoise, moonstone, and opal. This is usually the final step in converting a rough mineral into a scintillating gemstone that can be adorned in jewellery.
Step 4: Distribution & Retail
The gemstone industry includes multiple tiers of sellers who participate in the process prior to the sale of gemstones to end consumers. These tiers may include miners, wholesalers, manufacturers, and retailers, among others. Each level of the supply chain plays a crucial role in bringing gemstones to market.
The first level is the mining companies that extract the gemstones from the earth. Once the gemstones are extracted, they are typically sold to wholesalers in large auctions who have the resources to purchase them in huge quantities.
Wholesalers then sell the gemstones to manufacturers who specialize in buying and selling rough gemstones. Some dealers may specialize in certain types of gemstones or cater to specific markets such as rare and exotic gemstones, coloured diamonds and so on. These dealers may also act as brokers, connecting buyers with sellers and negotiating deals on their behalf. These manufacturers then transform the rough gemstone minerals into polished gems or pieces of jewellery. This may involve cutting and shaping the gemstones, setting them into jewellery pieces, or creating custom designs for clients.
Retailers purchase gemstones from wholesalers or manufacturers and then sell them to the final consumer. Retailers may offer loose gemstones for sale or use them to create custom pieces of jewellery for their clients. In some cases, retailers may also work directly with gem cutters to create unique gemstones or designs.
The famous Chanthaburi gem market in Thailand
In conclusion, the gemstone industry is characterized by a complex and intricate journey from mine to market. The involvement of various people and processes at different stages of the supply chain is crucial to ensuring that the final product meets the needs and expectations of the end customer. This collaborative process, although simplified in this article, is one that requires exceptional time, effort, and resources.
