Aquamarine
Beryl var. Aquamarine · Precious Gemstone
Crystal System
Hexagonal; typically forms in long prismatic crystals with flat terminations.
Mineral Group
Silicates (Cyclosilicates); Beryl group
Chemical Formula
Be3Al2Si6O18 with trace Iron (Fe2+)
Formation Process
Primarily Igneous; found in granitic pegmatites and hydrothermal veins under high pressure.
About This Crystal
Transparent to translucent gemstone with a vivid light blue to cyan hue. Displays a vitreous (glassy) luster and contains visible internal 'garden' inclusions or fluid-filled fractures.
Physical Characteristics
Blue to blue-green color, white streak, 2.66-2.80 specific gravity, brittle tenacity, and non-fluorescent (typically) under UV light.
Optical Properties
Uniaxial negative; Refractive Index 1.572-1.590; Birefringence 0.005-0.009; Weak pleochroism from blue to colorless.
Hardness & Durability
Origin Region
Brazil (Minas Gerais), Pakistan (Shigar Valley), Madagascar, and Nigeria.
Hardness & Durability
7.5 to 8.0 on the Mohs scale; Good durability for jewelry but susceptible to fracture from sharp impact.
Care & Maintenance
Clean with warm soapy water; avoid ultrasonic cleaners or steam if inclusions are present. Store away from sunlight as heat can alter color.
Rarity & Value
Common to Uncommon; value is driven by the 'Santa Maria' blue saturation level, clarity, and stone size. Heat treatment is standard to remove yellow tones.
Special Characteristics
Often features 'rain' inclusions (long parallel hollow tubes) and may exhibit chatoyancy (cat's eye effect) in rare translucent specimens.
Lore & History
Historically known as the 'sailor's stone' for protection at sea. Ancient Romans believed it could cure throat and stomach ailments. Symbolizes tranquility and clarity.