Aquamarine

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Aquamarine
Chemical composition Be3Al2(SiO3)6 Beryllium aluminum silicate
Crystal system Hexagonal
Habit Prismatic
Cleavage Imperfect, basal, almost never seen
Hardness 7.5 to 8
Optic nature Uniaxial -
Refractive index 1.577-1.583
(+0.017, - 0.017)
Birefringence 0.005-0.009
Dispersion Low, 0.014
Specific gravity 2.72
(+0.18,-0.5)
Lustre Vitreous
Pleochroism Weak to moderate

Aquamarine is a pastel greenish-blue variety of the mineral beryl and owes it's color to the presence of iron impurities. Its name is derived from the Latin words for water (aqua) and sea (marine). Crystals form in large hexagonal prisms. In ancient times, it was believed that sailors wearing aquamarine pendants would be protected from the perils of the sea. The stone symbolized happiness and eternal youth. It was viewed in Christian symbolism to bring moderation and control of passions to its owner.

Beauty is in the eye of the beholder

In the past, the natural greenish-blue color of aquamarine was considered the most desirable. Today, the usual color that we see of Aquamarine is a pale pastel blue. The most sought after color is a deep blue, as typified by the "Santa Maria", "Santa Maria d'Afrique" and "Marta Rocha" aquamarine finds.


Treatments

Routinely heat treated, which removes the green cast, leaving only the blue.

Typical inclusions

Rain inclusions