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BerylBack to A - Z IndexChard 24 Carat Home Page

Large Square Cut Cornered Emerald
Emerald is a Variety of Beryl


Beryl exists in a number of different varieties, some being better known by their own name, for example, emerald is the grass green variety and aquamarine is the sky blue variety.
The varieties of beryl and their colours are as follows:
Grass greenEmerald
Sea blueAquamarine
YellowHeliodor or Golden Beryl
Pale GreenBeryl

All the stones listed in the above table are different varieties of beryl, and share many characteristics.
While all emeralds and aquamarines are beryl, not all beryls are emeralds or aqua's.

Pure beryl is colourless, often called white, and although quite rare, tends not to be valuable because it does not have much brilliance. Colours, as in many gemstones, are caused by small amounts of impurity, usually metallic oxides. This is another case where impurity is desirable.
Chromium, in the form of chromic oxide, causes the bright grassy green colouring in beryl, thereby producing beryls.
Vanadium can also affect the exact shade, as may traces of iron.
It is also possible to have green beryl which is not emerald, because the colouring agent is not chromium.

More Variety
For more about each variety, please see the separate pages we have created for them.

Beryl is quite hard, having a hardness of 71/2 to 8 on Moh's scale, compared with 10 for diamond, 9 for corundum, and 8 for topaz. Hardness is generally a desirable feature is gemstones.

The price range of beryls is very large, ranging from under £1 pound per carat.

Beryl jewellery can be carefully cleaned using warm soapy water, or detergent, rinse thoroughly afterwards as detergents can cause dermatitis and allergic reactions. Enzyme cleaners should be avoided for the same reasons. Brushing with an old tooth brush to remove dirt and grease will also help. Cleaning agents containing chlorine may have a detrimental effect on low carat gold alloys, so are best avoided.
We stress that reasonable care should be taken when cleaning emeralds, as washing with strong detergents could cause any oil to be diluted or removed, requiring the stone to be re-oiled.
Beryls do not like excessive heat, and although they can tolerate temperatures above 100c (the boiling point of water), it is advisable to use warm water rather than hot water, to reduce the dangers of thermal shock.
It is not advisable to clean beryl in an ultrasonic tank. We sometimes risk it with our own stock, but we would never clean a large or valuable beryl which did not belong to us, in an ultrasonic machine.

Repair Work
Because of beryls sensitivity to high temperatures and rapid temperature change, it is somewhat risky to carry out soldering close to beryls when carrying out jewellery repairs. It is possible for beryls to be coated with borax, or proprietary heat-shielding material while carrying soldering work on the jewellery in which they are set, but this must be done carefully, and if the beryls are large or of very high quality, it is better to unset them before carrying out repair work involving heat. Naturally this itself carries some degree of risk. For this reason, it is best to treat beryl jewellery with greater care and respect than for tougher stones such as diamond, sapphire or ruby.
The mounts should be of good quality alloy such as eighteen carat gold or platinum, not nine carat. Expect to pay more for repair work on beryl jewellery than for similar work on other stones.

Technical Data
Chemical Composition and NameBe3Al2(SiO3)6 - Beryllium Aluminium Silicate
Hardness7.5 to 8
Refractive Index1.560 - 1.565 to 1.590 to 1.599
Specific Gravity2.65 to 2.85
Birefringence0.005 to 0.009
Crystalline SystemHexagonal
Optic SignNegative
Other Optical PropertiesUniaxial the Lowest Possible Price

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