Aquamarine – a buying guide to the ocean blue gemstone
The name aquamarine is derived from the Latin for ‘water of the sea,’ and it has long been associated with the colour and mythology of the ocean. Aquamarine are part of the beryl family of gemstones, which includes emerald, and they derive their colouration from the presence of iron in their crystalline structure, whereas emeralds are coloured by traces of vanadium and chromium. The quantity of iron contained within an aquamarine determines the depth of its ‘blueness,’ ranging from near transparent through to a much deeper tone. Furthermore, aquamarine displays a pleochroism, that is to say it gives off different tones of blue from different angles. Aquamarine is also one of the harder beryl species, so it is less prone to chip than emerald. In antiquity aquamarine were said to have possessed the souls of mermaids and could be bestowed upon sailors that were lucky enough to encounter them, granting protection from the violence of storms. Aquamarine became extremely popular during the Victorian and Edwardian eras, when it adorned the collections of all the great houses of Europe and beyond. This popularity continued throughout the Art Deco period and the interwar years, as they became the stone of choice for many of the nascent Hollywood stars. Brazil is generally regarded to be the origin of the finest examples of aquamarine but good quality stones are also found in Nigeria, Kenya, Madagascar, Zambia, Tanzania, Afghanistan and Russia. The most famous (and largest known cut specimen) is the ‘Dom Pedro’ aquamarine which, at a vast 10,363 carats, was won from a 45KG crystal in Pedra Azul, Minas Gerais, Brazil in 1980. It now resides in the Smithsonian Institute in Washington DC.
(An aquamarine seem at a open cast mine in Minas Gerais, Brazil)
Queen Elizabeth II has a fine collection of aquamarine, part of which was gifted her from the Brazilian government at her coronation in 1953. These pieces inspired her to acquire more and she is now one of the most prolific collectors of aquamarine jewellery. Many styles of aquamarine ring exist but the most popular is inspired by an Art Deco ‘stepped’ emerald cut shapes. The first surviving reference to the use of aquamarine in jewellery dates back beyond 200 BC and Damigeron’s text on the ‘Virtue of Stones,’ which was one of the earliest examples of jewellery and gemstone literature. The stone itself is created when molten rock in the earth’s mantle and pegmatite react at very high temperatures. The size of the stones as they form is dictated by the speed with which the pegmatite cools. The faster the cool down period the smaller the resultant aquamarine. Aquamarine is found in its natural form in hexagonal, prismatic, short, wide and tabular crystals. At 7.5-8.0 on the (1-10) Moh’s scale of ‘hardness,’ aquamarine is fairly durable compared with many other beryl species. As is common practice with many coloured gemstones, aquamarine can be heat treated in order to deepen its colour and enhance its clarity. There is nothing wrong with purchasing a treated stone but it is advisable to look for examples that are accompanied by a world-renowned gemmological certificate. Most aquamarine are shaped into facetted cuts, in order to maximise the refraction of natural light and minimise the appearance of inclusions.
(Examples of rough aquamarine)
The most sort after aquamarine are those that do not possess secondary colours and are deep, vibrant and eye-clean, with no visible inclusions to the naked eye. Due to the fact aquamarine is often found in large formations (the largest rough stones ever discovered have been measured at over 100,000 carats), its price does not increase exponentially with carat size. As the market for aquamarine has grown over recent years, synthetic and artificial examples have become more common. The key difference between the two is that synthetic stones have the same chemical composition as their natural counterparts, whereas artificial stones are made from material that is completely different in its molecular and chemical structure and is, in effect, an imitation. One tell-tale sign that a stone is an imitation is the presence of small bubbles under the surface, which never occur in natural aquamarine because the huge pressures under which they are formed. Another common indicator, used by dealers for many centuries, relates to the temperature of the stone, which should be slightly lower than room temperature for it to be natural. As aquamarine is quite a durable stone, looking after it correctly is relatively straight forward. As with all gemstones and jewellery, it is better to keep them in a warm, dry environment in order to maintain them in the best possible material state. Occasionally wipe them with a dry cloth and do not use any form of detergent or chemical cleaning product, as these can damage the surface of the stones and metal.
It is also worth keeping jewellery items apart to avoid them coming into contact and scratching each other. Prevent excessive exposure of aquamarine to light, as this can diminish the delicate balance of colours within the stone. Every once in a while, it pays to conduct a slightly more involved cleaning process. This is achieved by soaking the stones in warm water for several minutes, prior to gently brushing them with a soft tooth brush to remove any surface layers of grease or grime that may have accumulated. In order to clean the metal work of the jewellery piece in which the stone is mounted, dry it thoroughly and then buff it with a soft jeweller’s cloth. If in any doubt, take it to a jeweller to be professionally cleaned but always avoid any form of ultrasonic cleaning, as this can cause fractures to open up within the stone. Aquamarine, the March birthstone, has long been connected with love and the endless allure of the deep blue sea. Find your perfect aquamarine from our vast inventory of gemstones and coloured gemstones via our website. It is also worth considering other erstwhile members of the beryl family, these include emerald but also the less well known yellow beryl, bixbite (a very rare red variety), helidore (a light yellow to orange stone) and morganite (which is found in light peach pink) among many others.
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