Aquamarine is in the beryl group of minerals. The most valuable and most well-known beryl mineral is emerald, and though these two gemstones share a similar chemical composition, their characteristics are very different. Emeralds have their brilliant green color due to chromium and vanadium, while aquamarine gets its blue to green-blue color from iron impurities. Its famous sea-blue tones can range in intensity from a pale light blue to dark-blue, which is the most sought after and valuable aquamarine color.
Aquamarine is relatively hard and durable, ranging from 7.5 to 8 on the Mohs scale. It can be cut into a variety of shapes, and is usually clear and transparent (another contrast to emerald, which often is full of inclusions and other impurities). Aquamarine has been found all over the world, with the biggest suppliers being Brazil and India. Unlike emerald, aquamarine has been found in large deposits with some of the chucks producing over 100,000 carats of gemstones from an initial rough weight of 243 pounds!
The 'Dom Pedro', weighing 26 kg and cut in Idar-Oberstein, Germany in 1992 by the gemstone designer Bernd Munsteiner, is the largest single piece of aquamarine to have ever been cut.
Though transparent specimens of aquamarine are considered the best quality of the mineral, there are some valuable exceptions. Sometimes specifically aligned minerals within the aquamarine can create a cat’s eye or star effect. Both of these effects are pretty rare, highly sought-after, and are generally cut into cabochons.
Perhaps the most favored cut of aquamarine is an emerald step-cut, as well as other types of square and rectangular cuts. Because of its hardness and durability, skilled gem-cutters can fashion aquamarine into most any shape, and also into ornamental figures.
Aquamarine is sometimes heat-treated at lower temperatures to reduce green and yellowish hues, but most pieces are left untreated. Generally, darker shades of aquamarine are almost always heat-treated, which will further enhance the gem’s intense blue color.
The official birthstone for March, aquamarine has been termed “the sailor’s lucky stone” for over a thousand years. Perhaps due to its sea-blue color, it was thought to have originated from mermaids’ treasure chests, and was used by sailors to ensure safe passage on their journeys, and to ward off sea-sickness. Aquamarine was also used in antiquity to aid with eye-inflammation, varicose veins, sore throat, and arthritis. Whether the stone does anything other than look beautiful remains to be seen, but aquamarine is one of the most popular and versatile gemstones on the market.
Cleaning your aquamarine is easy because of its hardness and durability. Just use a mild soap with a soft-bristled toothbrush or soft cloth and warm water. Rinse and dry, and remember to store your aquamarine in a fabric lined jewelry box, or wrap in a soft cloth to keep scratches at bay. Please remember to remove any jewelry when using cleaning chemicals such as bleach!