Usually, these south sea pearls are graded based by looking at them visually and in this post, we shall try to mention the criteria used for grading them.
Following are the grading system used for saltwater pearls.
- The nacre of the pearl should be 2 to 4 mm in size.
- Luster must be sharp having rating between excellent and very good reelection.
- Sources of reflected light should have crisp edges blurring or staining can be observed.
- On surface of each pearl blemish rate should be less than 10%.
- Earrings should be set to clean in front.
- On inspection strands must be mostly perfectly clean to eye.
- Near-perfect matching with little to absolutely no variation in luster, color, tone, shape or size.
- Nacre should measure between 2 to 4 mm thick.
- Luster should be mostly sharp between Very Good and Fair reflection rate.
- Pearl surface’s facial features need not be observed however overall face shape must be visible.
- Reflected sources of light have blurred or slightly satiny edges.
- On surface of each pearl blemish rate is less than 20%.
- Maximum 2 heavy blemishes can be allowed on 18” strand.
- Matching should be very good with little variation in tone, color, luster, size or shape.
- Nacre size between 2 to 4 mm thick.
- Luster must be Good to Soft and reflected objects must be blurred.
- Usually facial features are not observed on pearl surfaces.
- Sources of reflected light will have blurred edges.
- On each surface of pearl blemish rate is less than 30%.
- 2 to 4 heavy/deep blemishes can be allowed on 18” strand.
- Must have good matching with some variation in tone, color, luster, size or shape.
- Luster should be from fair to soft having lower rate of reflection.
- Source of reflected light can be blurry.
- In pearl surfaces all facial features may not be observed.
- On surface of each pearl blemish rate should be less than 40%.
- Throughout layout few heavy blemishes can be observed, but deep inclusions must not make up greater than 10-15% of total layout.
- Matching of fair to good with little variation in tone, color, luster, size or shape.