Enhancements and Treatments
Almost all sapphires, rubies and emeralds are treated in some way to bring out their natural beauty and protect their natural characteristics. Sapphires and rubies are thermally treated, and emeralds undergo a special oiling process. These are standard, established treatments which are accepted as routine in the jewelry industry.
Almost all gemstones for sale to consumers have been enhanced in some way. Those rare few that have not are at the very top end of the price range.
Types of Enhancements
Sapphires - Sapphires are commonly heated to high temperatures to improve the color and clarity of the stone. This is essentially an extension of a natural process which took place over millions of years to form the stone. This treatment is a permanent enhancement.
Emeralds - Oils or paraffin are typically added to emeralds to enhance the clarity of the stone. The process masks some of the inclusions, and allows the beautiful emerald color to shine through. Resins and hardeners are used with this process to make the enhancement more permanent than oiling alone.
Rubies - Rubies are commonly heat treated to enhance their red color and make it more intense. Heating only enhances a ruby if the stone is chemically suitable. If the particular stone does not already contain the right chemistry, heating it further will do nothing to enhance its qualities. Any enhancement brought about by heat treatment is permanent.