Aquamarine – The Birthstone for March

 

As you would expect from a gemstone whose name means sea water, Aquamarine is reminiscent of the cool blue waters of the Mediterranean Sea and is the official March birthstone. It is a member of the Beryl family. Unlike the Emerald, also a beryl crystal, which is usually heavily included or flawed, Aquamarine tends to form more commonly in spectacular crystals that are very clean by comparison. It forms some of the most stunning mineral masterpieces.

African Aquamarines

Recently, deposits of fine Aquamarine have been discovered in Africa. Most of these sources are mined by intrepid artisanal miners. This video tells the story of one such miner in Kenya.

The historical source of aquamarine in Africa was Madagascar. In the 1980’s, Zambia surprised the world with aquamarine that was rated 9.5 on a scale of one to ten. Mozambique followed in the mid – 90’s and was later joined by Nigeria in producing the enviable rough. This established Africa as a leader in quality and quantity of excellent Aquamarine that were comparable to the Brazilian deposits that were famous in the 1950s. More recently, there have been discoveries of various deposits from the African countries of Tanzania and Kenya. The map below shows the main deposits of Aquamarine in Africa.

 Geology

Aquamarine, being a Beryl is closely related to Emerald in the gem kingdom. Most of the East African Aquamarines formed during the Panafrican orogeny 500-600 million years ago. As such, they are some the oldest gemstones on the planet. During that period, there was neither flora nor fauna on earth. During the Panafrican orogeny, several continents and microcontinents amalgamated to create a super continent called Gondwana. The collision of several continents caused the Mozambique belt to form. This famous geological formation is a zone of tectonically and thermally highly stressed metamorphic and magmatic rocks, which once was a huge mountain range reaching from Arabia through East Africa to Antarctica. Most gemstones of East Africa were formed by tectonic and magmatic activity during the formation of the Mozambique belt.

Aquamarine are found in large veins or dykes in this belt, consisting mainly of quartz, feldspar and mica – these are called pegmatites. The pegmatites formed from residual fluids (water and gases). By slowly cooling down rock forming minerals, e.g. quartz, feldspar and mica crystallised in the large magma chambers. What stayed behind formed a residual melt, which became more and more enriched in everything that did not fit in the normal rock forming minerals. This usually is water, gases and rare elements such as lithium, beryllium, boron, caesium, and fluorine. 

 

When the residual melt finally cooled down too, hydrothermal fluids exsolved and their increasing pressure broke the surrounding rock. The freshly formed cracks were then filled with quartz, feldspar, mica, and occasionally the rarer Aquamarine, forming a pegmatite vein.  

Aquamarine Lore

Legend has it that Aquamarine is the treasure of Mermaids possessing the power to preserve sailors at sea. This wonderful stone is also highly regarded in the metaphysical world. It is believed to have a powerfully soothing influence on relationships, particularly on married couples, believed to ensure a long and happy marriage. This is why it is considered such a perfect gift on a special Anniversary. 

BIRTHSTONE SALE: 12% OFF ALL AQUAMARINES!!

Pingbacks and trackbacks (1)+

Comments are closed