Aquamarine Crystal
Beryllium aluminum silicate (Be3Al2Si6O18)
The blue iron-bearing variety of beryl, forming clear hexagonal crystals prized both as specimens and as a March birthstone gem.
- Mohs hardness
- 7.5-8
- Color
- Pale sky blue to blue-green
- Type
- crystal
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Overview
Aquamarine Crystal is the natural crystalline form of aquamarine, the blue to blue-green variety of beryl. Its name comes from the Latin for sea water, reflecting its calm, watery color. The hue ranges from pale sky blue to deeper sea-green depending on iron content.
Crystals grow as elongated hexagonal prisms, often with flat or slightly pyramidal terminations and fine lengthwise striations. Well-formed, transparent points are prized as specimens, while clean material is faceted into gems.
Aquamarine is one of the most popular collectible beryls because large, clean crystals are relatively available and its color is gentle and appealing. It is the traditional birthstone for March.
Formation & geology
Aquamarine crystallizes mainly in granitic pegmatites, where beryllium-rich fluids fill open pockets and allow large hexagonal crystals to grow slowly. It also occurs in some hydrothermal veins and miarolitic cavities.
The blue to blue-green color is caused by traces of iron in the beryl structure; ferrous iron yields blue, ferric iron yields yellow-green, and most natural stones are a mix. Much commercial aquamarine is gently heated to remove green and yellow tints, leaving pure blue.
Key sources include Brazil (Minas Gerais), Pakistan, Afghanistan, Madagascar, Namibia, Russia, Nigeria, and Mozambique.
How to identify it
Identify aquamarine by hexagonal prismatic crystals, glassy luster, sky-blue to sea-green color, hardness 7.5-8, and a white streak. It shows distinct dichroism, looking bluer when viewed down the length of the crystal.
It resists scratching by a steel knife. Blue topaz is heavier and has perfect basal cleavage; aquamarine lacks that cleavage. Blue glass imitations are softer and may contain bubbles, while apatite is much softer at 5.
Refractive index around 1.57-1.60 and specific gravity about 2.68-2.74 confirm beryl. Natural striations along the prism and a six-sided cross-section are good field clues.
Uses & significance
Aquamarine is a major jewelry gemstone, faceted into rings, pendants, and earrings, with large clean stones being especially desirable because the color often deepens with size. It is the March birthstone and a 19th-anniversary gem.
Raw crystals and terminated points are popular with mineral collectors and in the crystal-healing market. Aesthetic specimens on matrix, especially from Pakistan and Namibia, fetch strong prices.
Metaphysically, aquamarine is linked to calm, communication, and the sea, and was historically carried by sailors for protection. These associations are traditional rather than scientific.
Frequently asked questions
What gives aquamarine its blue color?
Traces of iron in the beryl crystal structure produce the blue to blue-green color; ferrous iron gives the prized pure blue.
Is raw aquamarine the same as the gemstone?
Yes. Aquamarine crystal is the natural form; clean portions are faceted into the familiar blue gemstone.
How can I tell aquamarine from blue topaz?
Topaz is denser and has perfect basal cleavage, while aquamarine lacks that cleavage and shows strong blue dichroism along its length.
Is aquamarine often treated?
Much aquamarine is gently heated to remove green and yellow tones, producing a purer blue; this is a stable, accepted treatment.
Aquamarine Crystal guides
In-depth guides for identifying, valuing, and understanding Aquamarine Crystal.
Aquamarine Crystal identified by the community
Real specimens identified with Rock Identifier.
