Although ruby is found in many places in the world, all ruby is judged by the finest material that comes from Burma. This material shows a fluorescence in daylight that gives its color a special vibrancy that rubies from other locations in the world do not have. The best color has been described as "pigeon's blood" which is a true red with a hint of blue. All other rubies are judged against this color standard. A fine ruby with excellent color that actually comes from Burma commands a premium and MUST always be accompanied with a laboratory certificate from a respected international gemological laboratory. When one can be found that also has brilliance and clarity and is also over one carat in size, the price goes well above the price for comparable diamonds. This quality is extremely rare and should only go to individuals who appreciate the unique and special circumstances that came together to produce this one of a kind gem miracle.

Since ruby is so expensive in the finer qualities, since the turn of the century (1900's) it has been synthesized. Just because a piece of jewelry is old, does not mean that the ruby found mounted in it is natural. It could be synthetic. Early synthetics are easy to detect and any competent gemologist can tell the difference. But the newer synthetics have been formed in the laboratory using similar processes as found in nature produce very real looking stones that take some expertise to distinguish. However, a good gemological laboratory can tell the difference and it is important because natural ruby is so expensive and the synthetic is not.

Rubies can also be found that will show a six point star when cut in a cabochon shape (domed). As in sapphires which also show this phenomenon, star rubies form due to the presence of another material, usually rutile, within the gem's molecular structure. This material follows the natural hexagonal crystal pattern of ruby and therefore when cut in a cabochon, will exhibit a star pattern. These star gems are judged on the sharpness of the star, its centered location, and whether all six "legs" are straight and go all of the way to the girdle. In addition, the star shows better against a dark red background so the body color adds value as well. Star rubies vary in body color from a reddish gray to dark red with the redder tones being more valuable.