Aquamarine, like emerald, heliodor, and morganite, is part of the beryl group.  Its name, which means “water of the sea” comes from the Latin words aqua (water) and mare (sea).  Most aquamarines are found in granite pegmatites, which form as liquid molten rocks that rise through fissures and cracks in the Earth’s crust.   The stone’s distinctive blue comes from traces of iron interacting with light.   Brazil is currently the prime source for aquamarines. Extraordinary crystals have been found there, including a 550,000-carat aquamarine crystal that was found in 1910.  Though, sky-blue and dark blue stones are now the most highly prized, in the 19^th century, sea-green stones were preferred. Most aquamarines today are heat-treated, which removes the green hues, resulting in a purer blue.

Astrology:   March birthstone, connected to Pisces; prior to the 15^th century, it was the October birthstone

Chakra: 5^th (throat), and helps align the chakras

The gentle blue of aquamarine combines beautifully with pearls, rose quartz, peridot, pink or white coral, pink or green tourmaline, golden topaz, green jade, or a lavender amethyst. For contrast, try black onyx or labradorite.   And for a lovely summery piece, combine aquamarine with pearls, smoky quartz, and blue-green chalcedony or chrysoprase.

Color: Light blue, blue, blue-green

Chemical composition: Al₂Be₃(Si₈O₁₈) aluminium beryllium sliciate

Mohs’ hardness: 7 ½-8

Transparency: Transparent to opaque

Luster: Vitreous

Fracture: Conchoidal, uneven, brittle

Crystal system: Hexagonal (trigonal); long prisms

Cleavage: Imperfect

Specific gravity: 2.67-2.71

Refractive index: 1.577-1.583

Dispersion: 0.014

Pleochroism: Definite, nearly colorless-light blue

Fluorescence: None

Occurrence:  Afghanistan, Australia, Brazil, India, Kenya Malagasy Republic, Myanmar, Nigeria, Pakistan, Russia, Sri Lanka,  and the United States (Colorado).