March Birthstone - Aquamarine

Physical and Chemical Properties

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Chemical composition

Aquamarine is the mineral Beryl, a Beryllium Aluminum Silicate with the general chemical formula Be3Al2(Si16O18). It ranges in hardness from 7 2 to 8 on Moas scale; it has an imperfect cleavage and a vitreous luster. Optically, beryl is uniaxial negative; some specimens may be strongly diachronic; its refractive index ranges from about 1.57-1.58 or to 1.58-1.59. Aquamarine crystals are often elongated along the c-axis whereas emerald crystals are often blunted along the c-axis. This creates the effect of the former appearing wand-like or pencil-like whereas the latter may appear barrel-like. Other mineral beryls include emerald, morganite, and heliodor.

Colors

Aquamarine ranges from pale blues to light blues to yellowish blues and also may appear to be green or greenish-blue. They may be heat treated to intensify their color.

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