Ultimate Guide to Pearls-Grading Standards and Quality Control

White Color Grading

Natural Color Grading

Appendix 1. Grading standards for Freshwater&Fresh AK Pearls

White Color Grading

Natural Color Grading

Appendix 2. Grading standards for South Sea&Tahitian/&Edison Pearls

All 925 silver and k-gold jewelry should have stamps such as S925 and AU750.

The following four conditions, or any other issues that affect quality and aesthetics, deem a product as unacceptable. (For k-gold category, apart from the following conditions, all details, such as "surface, prongs, corners, gaps, ring openings, etc.," should be smooth, shiny, and perfectly round.)

• Deformation, surface pits, protrusions, defects, fractures, scratches, yellowing, discoloration, and lack of plating (including un-plated areas in ring walls and overlapping areas).
• Loss, tilting, insecurity, or surface damage of zircon or gemstones.
• Creases, fractures, or spring clasp damage (deformation, failure to rebound properly) on the chain.
• Notches, tilting, insecurity, or severe irregularity in ring openings.

• After setting, the pearls should adhere to the base securely and not dislodge when touched.
• Quality inspection should ensure no excess glue, tilting, or insecurity. If there is excess glue, it should be cleaned. Tilting or insecurity after setting is considered unacceptable.
• After completion of production, clean the product using a clean silver cloth/soft cloth before placing it into a self-sealing bag.
• Standard packaging includes jewelry tags + OPP bags/jewelry pouches, etc. If gift box packaging is desired, appropriate gift boxes can be purchased.

• Eusharon's stringing standard length is 40cm/16 inches. (As described in GIA: Stringing is generally 14 inches (35cm) or 16 inches (40cm), depending on the merchant's production. The market average is typically 38-40cm.)
• How to measure a necklace/strand: Measure the pearl diameter perpendicular to the drilling hole.
• How to indicate pearl size: Use millimeters (mm) as the unit.
• Necklace measurements have the largest size at the center and gradually decrease towards both ends. Sizes should not alternate or interchange. The size near the center should not be smaller than the size near the sides. For example, a 7-7.5mm necklace has 7.5mm pearls in the center and 7mm pearls at both ends.
• When stringing pearls, each pearl should be smooth and untwisted, and the strand should be knot-free. Use professional pearl thread or steel wire as needed.
• After production and quality inspection, print the product model label and attach it to the knot.
• Matching is the most crucial factor affecting product quality in pearl stringing production. Therefore, we have established strict matching standards to ensure product quality stability. For an explanation of grading terms, refer to the "Seven Factors Grading Chart."

GRADE	LUSTER	HUE(For White)	COLOR	SHAPE	SURFACE
AAA and above	Same Grade Match	Completely Consistent	Completely Consistent	Completely Consistent	Same Grade Match
AAA- and below	Neighbor Grade Match	Basically Same	Basically Same	Basically Same	Neighbor Grade Match

• Pearl quality requirements are the same as for stringing standards.
• Default necklace length is 18 inches (45cm), and bracelet length is 7.5 inches (19.5cm), including clasp and knots. Customers who require custom lengths should contact us (add contact hyperlink).
• Each pearl on a finished necklace should be tightly strung (not loose) and have a flat orientation (not twisted). The knot at the end should not be too visible, ensuring both aesthetic and structural integrity.
• For necklaces >5mm: Knot between each pearl, with two knots at the end.
• For necklaces ≤5mm with small pearls: No knots or knots tied directly at the loop of the clasp or using steel wire for production.
• Standard packaging includes jewelry tags + OPP bags/jewelry pouches, etc. If gift box packaging is desired, appropriate gift boxes can be purchased.