Luster is a combination of surface brilliance and a deep seated glow. This effect is created when light reflects off the many layers of tiny calcium carbonate crystals that compose the pearl. The luster of a good quality pearl should be bright and not dull. You should be able to see your own reflection clearly on the surface of a pearl. Any pearl that appears too white, dull or chalky indicates low quality.
  • Excellent (reflections appear bright and sharp)

  • Very Good (reflections appear bright and near sharp)

  • Good (reflections are bright but not sharp)

  • Fair (reflections are weak and blurred)

  • Poor (reflections are dim and diffused)


Blemishes or irregularities confined tot he pearl's surface, taking into account the size, number, nature, location, visibility, and type of surface characteristics.

  • Clean (blemish-free or containing minute surface characteristics that are difficult to see)
  • Lightly Spotted (only minor surface irregularities visible)
  • Moderately Spotted (noticeable surface characteristics)
  • Heavily Spotted (obvious surface irregularities that might affect durability)