Aquamarine
Beryl var. Aquamarine · Precious Gemstone
Crystal System
Hexagonal; typically occurs in prismatic crystals, though this specimen is an alluvial or weathered rough pebble showing a stubby habit.
Mineral Group
Silicates (Cyclosilicates)
Chemical Formula
Be3Al2Si6O18 (trace Fe2+ ions produce the blue-green color)
Formation Process
Igneous formation; primarily crystallizes within granitic pegmatites or hydrothermal veins during the late-stage cooling of magma at high temperatures.
About This Crystal
A translucent to near-transparent pale greenish-blue rough crystal. It exhibits a vitreous to waxy luster on weathered surfaces. The specimen shows internal fractures and iron-oxide staining (brownish streak) along a primary cleavage plane or fracture line. It lacks the sharp termination of a faceted gem, appearing as a water-worn or 'rough-sorted' mineral specimen.
Physical Characteristics
Color: Pale sea-foam green to light blue; Streak: White; Cleavage: Imperfect/Poor basal; Fracture: Conchoidal to uneven; Specific Gravity: 2.66–2.80; Fluorescence: Generally inert, but may show weak yellowish-green under LWUV in some varieties.
Optical Properties
Uniaxial (-); Refractive Index: 1.577–1.583; Birefringence: 0.005–0.009; Pleochroism: Weak to moderate (colorless to light blue/greenish-blue); Dispersion: 0.014.
Hardness & Durability
Origin Region
Commonly sourced from Brazil (Minas Gerais), Pakistan, Madagascar, and Nigeria; typically found in granitic pegmatites or alluvial deposits.
Hardness & Durability
Mohs Hardness: 7.5–8.0. It is a durable stone suitable for jewelry, though internal fractures (like those visible in the image) can make it susceptible to pressure.
Care & Maintenance
Avoid prolonged exposure to high heat and harsh chemicals. Clean with warm soapy water and a soft brush. Ultrasonic cleaners should be used with caution if internal fractures are present, as they may expand.
Rarity & Value
Common to Uncommon. Value is determined by color saturation (deeper blue is rarer), clarity, and size. Most commercial aquamarine is heat-treated to remove yellow/green tints, though this specimen looks natural and unenhanced.
Special Characteristics
Shows internal veining and slight iron staining. Can occasionally exhibit chatoyancy (cat's eye) or asterism, though not visible in this specific rough specimen. May contain liquid or gas-filled 'two-phase' inclusions common to beryl species.
Lore & History
Historically known as the 'sailor's stone,' believed to protect those at sea. Associated with the Throat Chakra in crystal healing, it is traditionally used to symbolize tranquility, clarity of communication, and courage. In ancient Rome, it was used to purify water and was gifted to brides to ensure long-lasting love.