Derived from the Latin words for water and sea, Aquamarine is aptly named for its serene blue-green colour. It is a variety of the mineral beryl (like emerald), forming sizeable crystals that make it an excellent stone for jewellery.
March’s birthstone has many ties to the sea, aside from its colour. Aquamarine is associated with the astrological water sign Scorpio and its soothing energy was said to calm sea waves, becoming known as the sailor’s gem. Ancient Greeks and Romans turned to the stone for safe passage on journeys across stormy seas.
Aquamarine was thought to bring a soldier victory during ancient battles, making the wearer of the stone invincible and in medieval times was said to reignite youthful love and passion in a marriage. Some modern day gift lists include the gem as a traditional 19th wedding anniversary present.
It is also considered an ideal gift for a groom to give his bride on their wedding day, along the lines of something blue, beyond something borrowed – Prince Harry gifted Meghan Markle a 30-carat emerald-cut pale blue aquamarine cocktail ring surrounded by diamonds which he inherited from his late mother, Princess Diana.
Folklore also describes aquamarine as an effective oracle stone, often used like a crystal ball for divination practices. Today, it is still a popular stone used in meditation, believed to enhance one’s intuition.
Aquamarine is formed in six-sided prismatic crystals, with the top quality historically mined in Brazil, as well as Sri Lanka, India, Afghanistan, Pakistan and Russia. The crystals tend to grow quite big, and a very large specimen weighing nearly 250 pounds, was found in Brazil in 1910.
A sky blue hue to a slightly greenish blue is the preferred colour for the gemstone in jewellery today, but in the past a greenish aquamarine was considered to be more valuable. The colour naturally comes from the iron content in the stone, which can appear blue, green or colourless depending on the light and angle. This is called a pleochroic effect. The deepest blue stones are called Santa Maria, named after the notable Brazilian mine.
Aquamarine gems used in jewellery today are commonly heat-treated to achieve the more sought-after deep blue colour. The colour and brilliance can also be enhanced by the cut of the stone.
On the Mohs hardness scale, aquamarine comes in at 7.5 to 8.0, making it fairly resistant to scratches and therefore suitable for more than just special occasions, being much more durable than its dainty appearance makes it seem.
As for clarity, faceted aquamarine is more valuable if transparent and free of visible inclusions; however, it is currently a trend to fashion “milky” or translucent aquamarine into unique frosted jewellery pieces, especially attractive in tumbled bead necklaces. Jewellery designers also take more imaginative liberties with one-off specialty cuts, although aquamarine is most often fashioned as emerald-cuts or ovals.
A ring, simply set with perhaps a few diamond side-stones flanking a single aquamarine weighing 15 to 20 carats, makes for a stunning bold display.