aguamarina

Aguamarina is a blue to blue-green variety of the mineral beryl (Be3Al2Si6O18). Its color ranges from pale blue to vivid blue-green and is caused primarily by trace amounts of iron. The name comes from the Latin aqua marina, meaning sea water.

Aguamarina crystallizes in the hexagonal system and forms prismatic crystals in granitic pegmatites and hydrothermal veins. It has a hardness of 7.5–8 on the Mohs scale and a specific gravity of about 2.68–2.74. It exhibits poor to indistinct cleavage and a transparent to translucent appearance.

Color and treatments: The blue color is often enhanced by heat treatment to remove greenish tints, yielding a purer blue. Some stones are irradiated to deepen the color. Inclusions can create a garden-like pattern; rare optical effects such as asterism or chatoyancy may occur in exceptional specimens.

Occurrence and sources: Major sources include Brazil (Minas Gerais and Bahia), as well as Nigeria, Madagascar, Mozambique, Zambia, Afghanistan, Russia, and the United States (notably Colorado and North Carolina).

Uses and value: Aguamarina is widely used as a gemstone in jewelry. Paler blues are common and generally less expensive; deeper blue hues are more sought after. Large, clean stones are rarer and can command higher prices. Most aquamarines are heat-treated to improve color, and proper care should be taken with heat exposure and cleaning methods.