Provenite

About Aquamarine

Be₃Al₂Si₆O₁₈

Aquamarine is the blue to greenish-blue variety of beryl; emerald is the green variety of the same mineral. Its colour is tied to iron: ferrous iron sitting in the open channels of the beryl structure absorbs in the near infrared, and an interaction between ferrous and ferric iron has been proposed for the more intensely blue beryls. Because it commonly grows as large, clear, well-formed prisms, it is a favourite of mineral collectors as well as a gemstone.

Show 45 localities on the map

Photos of Aquamarine

Doubly terminated gem aquamarine floater with muscovite, labelled Skardu, Pakistan.
Aquamarine · Skardu
Doubly terminated gem aquamarine floater with muscovite, labelled Skardu, Pakistan.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Small terminated aquamarine crystal 1.7 cm long from Mount Antero, Chaffee County, Colorado.
Aquamarine · Mount Antero
Small terminated aquamarine crystal 1.7 cm long from Mount Antero, Chaffee County, Colorado.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Large, doubly terminated, sceptred aquamarine crystal from Dassu, Shigar Valley, Pakistan.
Aquamarine · Dassu (Dusso)
Large, doubly terminated, sceptred aquamarine crystal from Dassu, Shigar Valley, Pakistan.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Chunky, doubly terminated gem aquamarine crystal at the edge of its matrix from Mogok, Myanmar.
Aquamarine · Mogok
Chunky, doubly terminated gem aquamarine crystal at the edge of its matrix from Mogok, Myanmar.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Gem aquamarine floater crystal 4.1 cm long from the La Esperanza Quarry, Dumesnil, Córdoba, Argentina.
Aquamarine · La Esperanza Quarry (Dumesnil)
Gem aquamarine floater crystal 4.1 cm long from the La Esperanza Quarry, Dumesnil, Córdoba, Argentina.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Aquamarine crystal 5.6 cm long with two terminations on the same end from Medina, Minas Gerais, Brazil.
Aquamarine · Medina
Aquamarine crystal 5.6 cm long with two terminations on the same end from Medina, Minas Gerais, Brazil.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Large, doubly terminated gemmy aquamarine crystal with muscovite, labelled Gilgit, Pakistan.
Aquamarine · Gilgit
Large, doubly terminated gemmy aquamarine crystal with muscovite, labelled Gilgit, Pakistan.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Tabular gem aquamarine crystals on matrix from Mt Xuebaoding, Pingwu County, Sichuan, China.
Aquamarine · Mt Xuebaoding (Pingwu)
Tabular gem aquamarine crystals on matrix from Mt Xuebaoding, Pingwu County, Sichuan, China.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source

Where Aquamarine is found (45)

Argentina

Brazil

Bulgaria

China

Colombia

Germany

Kenya

Myanmar

Namibia

Nepal

Nigeria

Pakistan

Russia

United States

Vietnam

Identity

Variety of
Beryl
Strunz
9 Silicates
IMA status
Variety
Elements
Be, Al, Si, O

Physical properties

Color
Pale blue to sky-blue and greenish blue; most often a light pastel greenish blue
Streak
White
Luster
Vitreous luster
Transparency
Variable
Mohs hardness
7.5–8
Density
2.63–2.97 g/cm³
Cleavage / fracture
Imperfect cleavage on {0001}; fracture conchoidal to uneven; brittle

Crystallography

Crystal system
Hexagonal
Space group
P6/mcc
Typical habit
Hexagonal prisms with {10-10}, {0001} and {11-20}, sometimes terminated by pyramids; also columnar to granular. Aquamarine often forms large, clean, well-formed crystals
Twinning
Rare, on {hkil} forms
Optical data
Uniaxial (-); nω = 1.567-1.610, nε = 1.565-1.599, rising with alkali content; pleochroism weak to distinct, with the extraordinary ray sea-green to blue in blue beryl

Formation and use

Formation
Like other beryl it forms mainly in granites and granite pegmatites (often in miarolitic cavities), rarely in nepheline syenites, and also in mafic metamorphic rocks, hydrothermal veins and vugs in rhyolite. Typical companions are quartz, feldspar, muscovite, lepidolite, tourmaline, topaz, spodumene, cassiterite and columbite-tantalite.
Uses
Gemstone; collector specimens.
Stability and care
Most aquamarine sold as gems has been heat-treated to remove the greenish tint and give a purer blue, although some buyers prefer the untreated greenish colour. Colour changes on heating and on irradiation are controlled largely by the iron in the structural channels.

Related minerals

Related minerals
Berylemerald

Sources

  1. SRC-266 · Book
    Handbook of Mineralogy - BerylAnthony, J.W.; Bideaux, R.A.; Bladh, K.W.; Nichols, M.C. · 2001 · Mineralogical Society of America / Mineral Data Publishing
  2. SRC-733 · Website
    Aquamarine DescriptionGemological Institute of America · GIA
  3. SRC-734 · Website
    Aquamarine Quality FactorsGemological Institute of America · GIA
  4. SRC-735 · Article
    Channel constituents in berylGoldman, D.S.; Rossman, G.R.; Parkin, K.M. · 1978 · Physics and Chemistry of Minerals 3, 225-235

Draft data from the Provenite workbook. Check entries against the cited sources before relying on them. Photos are open-licence images from Wikimedia Commons; the author and licence are given with each photo.