Before trying to evaluate a pearl, you should know what type of pearls it is. Each type has its own characteristics due to the specific forming condition. We normally classify pearls by origin, then grade them within the types they subjected to by luster, nacre thickness, surface quality, size, color and shape.
If you try to compare the luster of a South Sea pearl and an Akoya Pearl, it is possible that you will be disappointed with the former. Why? Because Akoya pearls are very famous for their outstanding brilliance, while South Sea pearls are much bigger than Akoya pearls.
The pearl grading factors are normally not considered equal. Some factors will be weighted to give more influence in arriving at a final grade. Grading is relative to the best attainable quality for a certain type .
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