Gemstones are beautiful. They might be naturally beautiful or they would have undergone some treatment to alter their appearance. As a consumer it is essential to know whether the gemstone which we are buying has been treated and by what process. Natural gem crystals in their original form cannot be used for jewelry. They have to be transformed from their rough crystallographic form into shapes, outlines and degrees that we appreciate and wear. The process of manufacturing gemstones always consists of these same steps. But beyond the traditional cutting and polishing gems can often be treated which alters their color and clarity. These treatments can improve or diminish the durability of the gemstone. It is difficult to find out whether the treatment has been done by naked eye. It is sometimes difficult for the experts to find out if any treatment has been done to the gemstone.
It is important for the buyer to know that the gemstone he is buying has gone through the treatment or not. The seller can sell the gemstone at a higher price than the normal price by misleading the consumer. The challenge which the consumer faces is that the treatments can be permanent, long lasting, or short-lived under normal jewelry use.
Here are few of the treatment process and how the treatment affects a particular gemstone
Bleaching
PROCESS:
In this process a chemical is used to lighten the color of the gem. Some gemstones are bleached and then dyed, a form of “combination treatment.” It is permanent and undetectable. No price difference exists as a result.
GEMS TREATED:
Pearl, ivory and jade
DURABILITY:
The structure of most materials is broken down due to bleaching. This can also cause breaking. To overcome this problem most bleaching is followed by impregnation to improve durability and strengthen perceived color.
WHAT TO BE CAREFUL OF?
Once the gems are bleached they tend to be more brittle. They should be kept in soft and dry environment. Human oils and liquids should be avoided for they can damage the surface.
Heating
Process:
This involves exposing the gem to high temperatures to improve on their color and clarity.
GEMS TREATED:
Amber, Amethyst, Aquamarine, Ruby, Sapphire, Topaz, Zircon
DURABILITY:
The heating treatment is durable and permanent for all the gems.
WHAT TO BE CAREFUL OF?
The heating procedure may make the gems a bit brittle than usual strength. The care should be taken with the gems which have edges or corners.
Surface Coating
PROCESS:
It involves applying paint or a coloring agent to the back surface of the gems. The idea is to alter the color of the gemstones.
GEMS TREATED
Diamonds, tanzanite, topaz, coral, pearls
DURABILITY
The coating adds to the durability of the gemstone
WHAT TO BE CAREFUL OF?
The coating can be scratched and may not be good for the underlying gem. Care should be taken that the coated gems do not come in contact with hard or abrasive objects. When the gems are not in used they should be kept away safely in a dry surface.
Dyeing
PROCESS:
The process involves introducing colored dyes fractured gems to change their color. These fractures are artificially created by heating the gem so that a non porous material can by dyed.
GEMS TREATED
Pearls and corals
DURABILITY
The durability depends on the quality of dye.
WHAT TO BE CAREFUL OF?
The dyes can be leaked if the pore is huge. If it comes in contact with uv rays the dye can be affected. Alcohol is other substance which may affect the dye.
Fracture or cavity filling
PROCESS:
The process involves filling up the fractures or cavities with a glass, resin, wax or oil to conceal their visibility. It also helps to improve the apparent clarity of gem materials, appearance, stability, or in extreme cases—to add to a slight amount of weight to a gem.
GEMS TREATED:
Diamond, Ruby, Emerald
DURABILITY FACTORS
The durability depends on the filler. Glass is more durable then oils or wax.
WHAT TO BE CAREFUL OF
Changes in air pressure, proximity to heat, or by exposure to chemicals can all affect the appearance of filled gems by potentially altering or removing the filler substance.
Impregnation
PROCESS:
To make a gemstone more durable and appealing, the surface of gemstone is permeated with a polymer, wax or plastic
GEMSTONES TREATED:
Turquoise
DURABILITY
They are durable thill the time they are not exposed to heat
WHAT TO BE CAREFUL OF?
Care must be taken not to subject gemstones with wax or plastic impregnations to heat since these will likely damage the material.
Irradiation
PROCESS:
It involves exposure of a gem to an artificial source of radiation to change its color. This process is sometimes followed by a heat treatment to further modify the color.
GEMSTONES TREATED:
Diamond, Topaz and Quartz
DURABILITY
The gemstones treated with irradiation tend to be strong and stay for long.
WHAT TO BE CAREFUL FOR?
There are no special care requirements for most irradiated gem materials.
Laser drilling
PROCESS:
The process involves using a narrow focused beam of laser light to burn an open channel from the surface of a diamond to reach dark inclusions. This is generally followed by the use of a chemical forced into the channel to dissolve or alter the appearance of the inclusion.
GEMSTONES TREATED:
Diamonds
DURABILITY
The laser drilling does not affect the durability of diamond.
WHAT TO BE CAREFUL OF?
There are no special care requirements for the diamonds treated with laser-drilling.