Aquamarine | |
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![]() Faceted aquamarine | |
General | |
Category | Beryl variety |
Formula (repeating unit) | Be3Al2(SiO3)6 |
Crystal system | Hexagonal (6/m 2/m 2/m) Space group: P6/mсc |
Space group | (6/m 2/m 2/m) – dihexagonal dipyramidal |
Identification | |
Formula mass | 537.50 |
Color | Blue or cyan |
Fracture | Uneven to conchodial |
Tenacity | Brittle |
Mohs scale hardness | 7.5 - 8 |
Luster | Vistreous |
Streak | White |
Specific gravity | Average 2.76 |
Optical properties | Uniaxial (−) |
Refractive index | nω = 1.564–1.595, nε = 1.568–1.602 |
Birefringence | 0.004 - 0.007 |
Ultraviolet fluorescence | None (some fracture-filling materials used to improve emerald's clarity do fluoresce, but the stone itself does not) |
Common impurities | Fe2+ |
References | [1][2] |
Aquamarine is a gemstone of the beryl (Be3Al2(SiO3)6) variety. It is colored bright blue or cyan due to the gem containing impurities of Fe2+ ions.[3]
Etymology
editThe word "aquamarine" comes from the latin term 'aqua marina' which means sea water.[4]
Aquamarine mines
editThe largest cut aquamarine was found in Minas Gerais, Brazil in the late 1980s.[5] It is considered an exceptionally rare gem due to its size, rich blue-green color, rare clarity, and distinctive cut.[5]
References
edit- ^ "Beryl: Beryl mineral information and data". web.archive.org. 2007-10-26. Retrieved 2019-09-26.
- ^ "Aquamarine beryl: The blue mineral Aquamarine information and pictures". www.minerals.net. Retrieved 2019-09-26.
- ^ "Beryl spectra". minerals.caltech.edu. Retrieved 2019-09-28.
- ^ "Definition of AQUAMARINE". www.merriam-webster.com. Retrieved 2019-09-28.
- ^ a b "Smithsonian To Display World's Largest Cut Aquamarine, the Dom Pedro". Smithsonian Institution. Retrieved 2019-09-28.