From Mine to Market – The Amazing Story of Aquamarine Gemstone
Many of us own beautiful jewelry pieces containing different gems. You must have also appreciated their beauty at some point but have you ever wondered from where these stones come? How are they made? Let’s find about one of the most admired semi-precious gemstones – Aquamarine.
As the name suggests, it possesses different shades of seawater color, from light aqua to dark blue with tints of green.
How are they formed in Nature?
Aquamarines are created in the presence of two major components: Beryl and iron.
- Beryl is comprised of beryllium aluminum cyclosilicate located in deposits known as granitic pegmatite. These pegmatites are large structures composed of interlocking minerals and rocks. As they hold high granite deposits, they are sometimes pushed outside through natural geological processes. Depending upon the impurities, different colors are produced such as yellow, white, red, green, and blue. However, in its purest form, beryl is colorless.
- When beryl deposits are cast in the presence of iron, the crystallization process turns them to turquoise or a blue color resulting in the foundation of aquamarine gemstones.
From Where Do Aquamarine Gemstones Come?
They are one of the most brilliant and incredible gems found in many countries around the world – Afghanistan, China, Kenya, Mozambique, Pakistan, Russia, and The United States. However, Brazil is a major supplier and has been declared the aquamarine capital of the world. Each locality produces a different color variation of aquamarine. For example – Santa Maria de Itabira mine in Brazil yields a rare and intense blue aquamarine gemstone, whereas Espirito Santo mine produces blue, but not bright, stones.
Aquamarine through Stages: Rough to Polished Gemstone
Aquamarine completes a long journey from rough stone to a polished gemstone. This process involves countless hours of labor and immense efforts.
The mining process starts from investigating the geological site and assessing the environmental impact of the mines that might offer aquamarine gemstone. Then, the identified landform is gently moved with a smooth wavelike motion above the sea level. This defined area holds metamorphic rocks under it that are composed of pegmatite veins, which in turn results in aquamarine crystals.
These minerals are found in multiple facets and bear inclusions. The pegmatite veins are fractured through an open cast mining method using pneumatic tools like Aquamarin jackhammers, chisels, ladders, etc. Finally, a bulldozer is used to carry out the complete extraction process.
Once the gemstone is separated from the rock, it is collected and cleaned off with water. All stones, when excavated, are uneven and unattractive. The whole procedure of cleaning is environment-friendly without the use of any toxic or harmful chemicals. Stones thus obtained from the mines are called rough aquamarine.
This rough stone undergoes the following techniques before transforming into polished gemstones:
- Sorting – Stones are segregated based on their size (larger or smaller), color (pale to brilliant), clarity (heavily included or flawless) and cut (the crystalline structure is hexagonal – six sided). The stones that are richly colored are the most desired stones, and the ones with pale coloration are customized into inexpensive jewelry.
- Gem Processing – This is one of the critical steps wherein rough stones are transformed into beautiful and attractive gemstones. This process involves a lot of experience, hard work, and potential. The stones are outlined on the slab, and the shapes are cut depending upon their resiliency. Usually, aquamarine gemstones are free from inclusions but if it has any fractures then those are separated with a diamond saw blade, and this process is called “sawing.” Good quality gem should be translucent and clear and not contain any flaw, such as a scratch.
- Pre-forming – Few gemstones possess sturdy and rigid crystalline structure and are difficult to cut. However, aquamarine gemstones can be cut to highlight the stone’s natural brilliance. Its hardness ranges from 7.5 – 8 on the Mohs scale, which makes them highly durable and resistant to scratches. Cutters often fashion them in emerald, round, oval or brilliant shapes using diamond grinding wheels.
After getting the desired shape, stones are colored by the color centers. Mostly, they possess natural blue-green to light sky blue color, but if the stone is yellow or pale, then they are heat treated to generate demanding bluish-green colors. The experts in specialized laboratories perform heat treatment, making the color stable and permanent. Aquamarine gemstone has a dichroic property (it displays more than one color when seen from different directions). To examine the stone, hold it up towards the light and see how the light strikes it from various angles. From one view, it may appear gorgeous blue, greenish, or greenish-blue while from another it may look colorless.