By Ronan 
Whenever you sell or purchase pearls a standardised system of grading should be used. However, there is no grading system adopted universally by the pearl industry and it totally depends on the type of pearls, jeweller or the pearl distributor.
The purchasing of various pearl ornaments like pearl necklaces, pendants, rings, bracelets and pearl earrings can be done efficiently if you have some knowledge about the pearl grading system. When you go to buy pearl jewellery you can always ask the seller to show you a written description of each grading system. Both of the grading systems mainly focus on the lustre, the quality of the pearl’s surface and the thickness of the nacre. There are mainly two pearl grading systems used extensively by every pearl retailer in the United States – AAA-A system and A-D system (Tahitian system)
Hanadama, AAA, AA, A system
This system was basically used for Akoya pearls and it grades pearls on a scale starting at A- Hanadama grade.
- Hanadama – It is a designation for the pearls that have cleared all the tests of Pearl Science Laboratory of Japan tests and must have an original certificate. Hanadama pearls should not have any defects and should have a high lustre.
- AAA – The pearls with this grading system are of the highest quality with high lustre. The pearls are round with a 95%free from defects.
- AA – Their surface is free from defect 95% and they have a good lustre.
- A – They are lowest jewellery grade pearl and their 25% of the surface shows defects.
- The A-D system or (Tahitian System)
This grading system makes use of a scale from A-D for grading the pearls. A is the highest grade. It was used in French Polynesia to grade the Tahitian pearls.
- A – Pearls with high-quality good lustre with very few imperfections are graded with this scale.
- B – Pearls with high and medium lustre are graded.
- C – Medium lustre with defects not more than 60% are graded.
- D – Pearls may have some slight defects but not deep ones. Even the most pearls with good lustre will be graded D if their surface is blemished.
Pearls which are below grade D are not used in jewellery. There are mainly two pearl grading systems used extensively by every pearl retailer in the United States. Both of the grading systems mainly focus on the lustre, the quality of the pearl’s surface and the thickness of the nacre.
Conclusion
So, it is very important to have knowledge about the pearl grading system as it helps the buyer and the seller to know about the fair price of the pearl and also about the quality.