Can a high quality blue sapphire be very dark,blue? Some jeweler told me w/all gems (ie:sapphire,ruby,emerald) all should be the darker the better, is this true?

Color and transparency is most important in all color gemstones.  However, if the gem is too dark -- for example, in a sapphire, the dark blue is inky, it would have a lower value than a medium dark blue that shows flashes of the vibrant blue color.  Keep in mind too, that when the gem is set, the stone will darken because less light is able to get through the gem.

For more information about gemstones, their characteristics, and values, contact Allen's Jewelers, an American Gem Society jeweler that educated in gem identification.