Introduction: Green beryl is a variety of the beryl species. Some green beryl is colored by iron displaying a color halfway between golden beryl and aquamarine. Ferric iron yields a yellow color while ferrous iron gives a blue color. Equal amounts of ferric and ferrous will impart a green color. This type of stone is pictured on the left, a green beryl from Brazil weighing14.90 ct Another type of green beryl is that which is colored by chromium but considered too light in tone to be called emerald. This green beryl is pictured on the right and weighs 1.37 ct. It also has interesting hematite inclusions.
Colors: Green. Most green beryls range from extremely light to medium in tone.
Clarity: Green beryl is of Type I clarity. By definition, gems of this type grow extremely clean in nature and usually have no eye visible inclusions. Typical inclusions are long hollow tubes. If these tubes are properly oriented when cutting en cabochon, it will display a cat’s eye.
Stone Sizes: Green beryl, similar to aquamarine, can sometimes form as large crystals capable of cutting stones in the hundreds of carats. Green beryls of this size are wonderful for collections and museum displays but have limited use in jewelry so larger gems are slightly lower in price per carat compared to the same quality green beryl used in jewelry.
Localities: Gem green beryl is potentially found in the same localities as aquamarine or emerald. Equal parts of ferric and ferrous to yield only the green is probably the exception as most will show a blue component and by definition be considered an aquamarine. Very light emerald can also be found from many of the emerald localities but would expect that most light emerald would be from Colombian or Brazilian sources
Treatments:
-No treatment (N) would be the case for the green beryl colored by iron while oiling/resin infusion (O) is possible for the green beryl colored by chromium.
Gemology:
-Refractive Index: 1.577-1.583 (+/- 0.017)
-Birefringence: 0.005 to 0.009
-Optic Character: Doubly refractive, uniaxial negative
-Dispersion: 0.014
-Specific Gravity: 2.72 (+0.18, -0.05)
-Hardness: 7.5-8
-Toughness: good
-Chemical Composition: Be3Al2Si6O18
-Cause of Color: Iron or chromium or chromium/vanadium
-Absorption Spectra: Not distinctive.
-Fluorescence: Inert
-Cleavage: Indistinct in one direction and almost never seen.
-Phenomena: Chatoyancy (somewhat common)
Name: Green beryl is simply a color variety of the species.
Dates: None.
Care: The ultrasonic and steam cleaner are generally safe unless the gem has liquid inclusions. Warm, soapy water is always safe.
To see available green beryls, click here. (None currently available)