At a glance, you can tell the quality of aquamarine by its colour. A deep hue of sea blue indicates the gem in front of you is most likely a premium quality aquamarine, but the colour of the stone cannot be its sole guarantor. You’ll need to check a few other technical factors to determine its actual quality and worth.
In this guide, we’ll share four factors that can help you assess the quality of aquamarine the next time you buy an aquamarine ring or pendant.
How Are Aquamarines Graded?
Before we explore the quality factors, let’s discuss the grading of aquamarine. Currently, most gem traders follow the non-GIA scale to grade these stones. According to this scale, aquamarines are categorised under the following:
- AAAA (GEM-grade)
GEM-grade or AAAA quality stones account for only 10% of aquamarines mined all over the globe, AAA-grade accounts for 20% to 30% of aquamarines mined, and 60% to 70% belong to double A grade or lower. Note that not all gem traders follow this scale–some may follow the GIA (standard) scale. Therefore, we recommend you inquire about the grading system from your jeweller.
What Are the Factors That Affect the Quality of an Aquamarine Stone?
Similar to diamonds, you can assess the quality of aquamarine using the four Cs–colour, clarity, cut, and carat.
As mentioned earlier, colour is the first thing that gives away the identity and origins of an aquamarine. If it’s colourless or pale blue, it’s likely a cheap variant coming from Pakistan. If it’s a mesmerising deep blue variant, it’s safe to assume it’s an expensive variant coming from Brazil.
Generally, the colour scale of aquamarines ranges from pale blue (almost colourless) to deep sea blue, and most of these are soft shades. Average quality aquamarines are usually greenish-blue or sea green in colour. As aquamarine is a pleochroic stone, meaning it shows different colours at different angles. Aquamarine’s pleochroism is subtle, so you can only expect to see slightly stronger or lighter hues at different angles. In some stones, the shade difference is so subtle that it’s indistinguishable.
With that said, most buyers prefer a deeper shade of blue-green on a budget, which is often considered the best colour of aquamarine. Some jewellers use an artificial means of enhancing an aquamarine’s colour–they heat it to get a deep blue hue, which is something you should bear in mind.
Top-quality aquamarines are usually transparent. You can see through them and easily locate any inclusions present. Because aquamarines belong to the beryl family, they may have liquid-filled inclusions that run parallel–gem experts call these inclusions “rain.” These inclusions are not usually visible to the naked eye, but if they’re in abundance, they can bring about the cat’s eye effect in the stone.
Through this effect, a band of light moves horizontally across the stone when you position it at different angles in a luminous environment. Any aquamarine exhibiting a proper cat-eye effect ranks as a top-grade specimen.
Due to their impressive Mohs Scale score, these stones exhibit excellent resistance to any abrasions or internal fractures likely to develop during the refinement process.
A high-quality aquamarine embodies any one of the most popular cuts of aquamarine–these include the Emerald cut and the Barion cut. These two cuts bring out the depth of an aquamarine’s natural colour and make the best of their pleochroic capabilities, meaning you’ll get to enjoy a new shade at every angle.
Apart from the type of cut, you should also assess the quality of the cut. Sharp and fine cuts are preferable, as they make the stone sparkle.
As a rule of thumb–when it comes to what determines the price of aquamarine–the greater the carat, the greater the quality and worth of a stone. One carat of good quality aquamarine costs around $675, while an average quality aquamarine will only cost you $100 per carat. Because aquamarines are more inexpensive stones, and you can easily get larger pieces of aquamarine at a reasonable price.
Unlike the grading system, quality factors are not disputed when it comes to a gemstone’s quality check. All gem traders go by these four factors to assess the worth of a gem. As a consumer, you can also count on these factors if you want to assess the quality of the stone you’re purchasing; you’re not using microscopes, so your approach won’t be as technical as that of a jeweller.
It can be tricky to determine the differences between a good-quality and premium-quality aquamarine, but these four factors will be enough to help you make the distinction. Of course, our jewellery experts at Holloway Diamonds are ready to help.