Genuine Natural
genuine gemstone = 100% natural gemstone... yes or no?
so, it's not like treated or dyed or heated or whatever?
I can't believe I just said or whatever
A genuine gemstone does NOT mean the same thing as a 100% natural gemstone.
Both a genuine gemstone and a 100 % natural gemstone are products of mother nature--they were grown in nature. This differs from a laboratory grown gemstone which is the same in its chemical properties as a gemstone grown in nature, but has been grown by man in a controlled laboratory setting.
A genuine gemstone can be genuine and still be treated in any number of ways, including irradiation, heat, dyed, etc.
For example, a Blue Topaz is a genuine gemstone, however it is ALWAYS treated. A genuine Blue Topaz is a white topaz that was grown in nature and then was treated to change it to the blue color.
Another example is Citrine. Most genuine gemstone citrines on the market today are amethysts that have been super-heated to change the color to the citrine gold/yellow. Still a "genuine" gemstone, just not a 100% "natural" gemstone.
Another good example of genuine gemstones--this time cabochons, not faceted--that have been treated is turquoise. Much of the most desirable "genuine" turquoise has been treated--it's been stabilized--to prevent color-change due to its softness and absorbency. While not 100% "natural", the stabilized genuine turquoise is still sought after and considered very appropriate for use in jewelry.
A good resource to learn more about gemstones is the book "Gemstones of the World" by Walter Schumann.