Aquamarine
Beryl var. Aquamarine · Precious Gemstone
Crystal System
Hexagonal; typically forms in elongated prismatic crystals with flat pinacoid terminations. Often found as water-worn pebbles or chunky crystal sections.
Mineral Group
Silicates; Subgroup: Cyclosilicate
Chemical Formula
Be3Al2Si6O18 with trace amounts of Fe2+ (ferrous iron)
Formation Process
Igneous/Hydrothermal: Forms primarily in pegmatite veins through the late-stage crystallization of magma and hydrothermal activity in cavities.
About This Crystal
Transparent to translucent specimen with a pale blue to greenish-blue hue. Vitreous (glass-like) luster, showing internal fractures and iron-stained surface cracks. The shape is somewhat irregular and slightly abraded.
Physical Characteristics
Color: Pale blue/cyan; Streak: White; Cleavage: Imperfect/indistinct basal cleavage; Fracture: Conchoidal to uneven; Specific Gravity: 2.66–2.80; Tenacity: Brittle; Fluorescence: Generally inert.
Optical Properties
Refractive Index: 1.577–1.583; Birefringence: 0.005–0.009 (uniaxial negative); Pleochroism: Weak to moderate (colorless to light blue); Singly or doubly refractive: Doubly refractive.
Hardness & Durability
Origin Region
Brazil (Minas Gerais), Nigeria, Madagascar, Pakistan, and the Ural Mountains in Russia. Often found in granitic pegmatites.
Hardness & Durability
Mohs Hardness: 7.5–8.0. Excellent for jewelry, though internal fractures (as seen in image) can reduce overall toughness and make it susceptible to breakage if hit hard.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid ultrasonic or steam cleaners if there are internal fractures. Store away from harder stones like Sapphire or Topaz. Avoid extreme heat.
Rarity & Value
Common to Uncommon. Value is determined by color saturation (deeper blue is more valuable), clarity, and size. Heat treatment to remove green tones is common and widely accepted.
Special Characteristics
Can exhibit chatoyancy (cat's eye) or asterism if needle-like inclusions are present. This specific specimen shows iron staining in surface-reaching cracks and internal 'ice' inclusions.
Lore & History
Historically known as the 'Sailor's Stone,' believed by ancient Greeks and Romans to protect those at sea. Symbolizes tranquility and clarity. Associated with the Throat Chakra in traditional healing practices.