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Chemical Properties of Aquamarine

Aquamarine is one color of the mineral beryl, which is a crystalline gemstone derived from beryllium aluminium cyclosilicate. Aquamarine is blue-green in color due to various impurities ingrained within the mineral during its crystallization process. Aquamarine can be found in a number of different areas of the world, though some of the finest deposits have been discovered in Russia and Sri Lanka. Aquamarine is the birthstone for the month of March.

Chemical Composition
- Aquamarine, and beryl in general, is composed of atoms of beryllium, aluminum, silicon and oxygen. The chemical formula for beryl is Be3Al2SiO6.
Color
- Due to impurities ingrained in the crystal, aquamarine appears in various colors such as light blue, blue-green, turquoise and sea-green.
Crystal Shape and Size
- Aquamarine develops into crystals of dihexagonal shape of anywhere from several millimeters to several meters in size. Crystals can be flattened due to external pressure, and can also become vertically striated or grooved, depending on their environment.
Refractive Index
- Aquamarine has a refractive index of 1.57 to 1.58. This is the measure of the speed of light within a substance expressed as the ratio of light speed in a vacuum to light speed within that substance. This compares to an index of 1.33 for water and 1.58 for polycarbonate.
Specific Gravity
- Aquamarine has a specific gravity, or relative density, of between 2.6 and 2.8. This puts it in the realm of certain building materials such as bricks and cement.
Hardness
- Aquamarine is a relatively hard mineral, measuring between 7.5 and 8 on the Mohs scale of mineral hardness. This puts it even with minerals such as quartz.

Rocks & Minerals