Fine Jewellery Atelier
Aquamarines
Aquamarine is one of the birthstones of March. Its name was derived from the Latin words Aqua Marina, which means seawater, and is widely believed to hold the powers of the sea. Aquamarine is part of the Beryl family of gemstones. It is one of the more popular Beryl varieties, alongside other gemstones such as Emeralds and Morganites.
History & Lore
The largest gemstone quality Aquamarine ever mined is the Dom Pedro which has a dimension of 42cm by 48.5cm, weighing a total of 110 Kg. It became the largest faceted Aquamarine, and perhaps the most famous, after being faceted by the ‘Father of fantasy cut’ Bernd Munsteiner. The end result was a spectacular 10,363 carats green-blue gemstone fashioned in the shape of an obelisk, valued by some at USD 6 million based on weight. However, the actual value of the piece is immeasurable. It is named after Brazilian Emperors Pedro I and Pedro II, and is currently on permanent display at Smithsonian Institution’s National Museum of Natural History in Washington, D.C.
Colour
Naturally, Aquamarines can range from blue to green-blue in colour, with its saturation the main factor in determining its rarity and price, like all other coloured gemstones. Pastel coloured Aquamarines generally would not fetch similar prices compared to their highly saturated counterparts. The most desired colour by collectors is a highly saturated blue, or otherwise known as ‘Santa Maria’ Aquamarine in trade terms.
Clarity
Aquamarines generally have less inclusions and have more well-formed crystals then other precious gemstones such as Rubies or Emeralds. This makes it exponentially easier to find an eye clean Aquamarine than Emerald although they both belong to the same Beryl family. This also means that Aquamarine is mostly faceted because of its great clarity that allows good brilliance after cutting. Some crystals might contain liquid inclusions, but these kind of inclusions are few or absent in most faceted Aquamarines. The most common type of inclusions in Aquamarines are the thin white streaks also known as the 'raindrops'.
Aquamarines also exists in larger crystal sizes compared to other precious gemstones such as the corundum varieties, which means it is easier to find a 10 cts Aquamarine than a 10 cts Sapphire or Ruby. Aquamarines can be cut into many shapes, round, princess, oval, cushion, pear with the most popular cut in the market being the emerald cut - a rectangular shaped step-cutting style.
Origin
Aquamarines can come from many origins, Colombia, USA, Madagascar, Kenya, and others but the most prominent source is Brazil. Brazil has been the main source of gem-quality Aquamarines since 1811. The Brazilian mines are where the biggest and highest quality aquamarines are mined, which includes significant stones such as the Papamel and Dom Pedro. Most Aquamarine mines are located in Northeast Minas Gerais, Brazil. Parkistan is another significant producer of Aquamarine.
Treatments
Most Aquamarines on the market have been heat treated, untreated Aquamarines generally have a bluish-green colour as opposed to what the public perceives as the blue ‘Aquamarine’ colour. Heat treatment of Aquamarine is done in low heat, and results are stable (will not fade) and widely accepted by the industry. The heating process removed the green hue in Aquamarines. Also as low heating (400-500 degrees Celsius) is undetectable in Beryls, be careful when a dealer tells you that an Aquamarine of certain colours are unheated. Like the Aquamarine, other gemstones in the Beryl family are also heated. Morganites are heated to remove yellow tones, Heliodors are heated to reduce golden tones.
Also, there have been recent reports of Aquamarine being fracture-filled. This treatment of using glass or resin to fill in cracks in gemstones is infamously used in Rubies, and is not accepted in the industry. However, as the prices of Aquamarines have increased over the years, some dealers are finding it profitable to fracture-fill these Aquamarines too.
Synthetics
Synthetic Aquamarines exist, but is not often seen on the market due to it being uneconomical to produce.
Care
With a Mohs scale rating of 7.5-8, Aquamarines are durable gemstones for jewellery as long as it is treated with care, as required by any gemstone, to prevent against scratching and hard knocks. Cleaning of Aquamarines should be done using warm soapy water and a soft brush. It can also be cleaned in an ultrasonic machine only with the condition that the gemstone has no liquid inclusions or fractures and is not fracture-filled. Exposure to heat is also not recommended for Aquamarines, which may cause discolouration.