What is Aquamarine

What is Aquamarine - The Birthstone for March

Aquamarine is the blue to green-blue variety of the mineral beryl, with the chemical formula Be₃Al₂Si₆O₁₈. Its colour is created by trace amounts of iron within the crystal structure, producing the serene ocean-like hues for which the gemstone is renowned.

Aquamarine crystallises in the hexagonal crystal system and often forms as large, well-defined crystals, making sizeable gemstones more readily available than many other precious gems. With a hardness of 7.5–8 on the Mohs scale, it is well suited to everyday wear. Its exceptional transparency and moderate refractive index create a bright, clean brilliance rather than the intense fire associated with diamond.

From a gemological perspective, aquamarine is assessed according to colour, clarity, cut, and size, with colour being the most significant factor influencing value. The finest examples display a rich, vivid blue, while most aquamarines naturally occur in lighter tones. Unlike its close relative emerald, aquamarine is typically very clean, with inclusions being comparatively uncommon.

Because aquamarine's colour is often delicate, skilled cutters carefully proportion the gemstone to maximise brightness, visual depth, and colour saturation. Heat treatment is commonly applied to enhance the blue appearance by reducing greenish undertones. This treatment is permanent, stable, and widely accepted within the international gem trade.

Beyond its beauty, aquamarine provides a fascinating example of the relationship between geology and gemology, demonstrating how trace elements within a crystal structure can create the colours that make gemstones so captivating.

Birthstone: March
Mineral Family: Beryl
Chemical Formula: Be₃Al₂Si₆O₁₈
Hardness: 7.5–8 Mohs
Crystal System: Hexagonal
Typical Treatments: Heat treatment to enhance blue colour
Primary Sources: Brazil, Madagascar, Nigeria, Pakistan, Mozambique, Zambia, and Afghanistan.