There are five key factors that determine the quality of a pearl:
LUSTRE
‘Lustre’ refers to the shine of a pearl. A pearl with a good lustre is often described as looking as though it is ‘glowing from within’, whereas a pearl with poor lustre will look somewhat flat and dull. When examining pearls, try and look at them in a natural light to see how well they reflect the light: the sharper the reflection, the better the lustre.
COLOUR
SIZE
Just like with diamonds, the value of the pearl is not wholly determined by the size but rather their rarity, but as a general rule the larger the pearl the higher the price tends to be.
SURFACE
SHAPE
There are three main shapes of pearls: round, drop and baroque. Perfectly round pearls are the most desirable and therefore more expensive.