One of the most confusing aspects of buying pearls is understanding grading systems. Unlike diamonds, which have a universally recognised grading standard (the 4Cs from GIA), pearls lack a single, industry-wide grading system. Different sellers use different scales, and the same grade can mean very different things depending on who's doing the grading.

This guide will help you navigate the various pearl grading systems, understand what each grade typically means, and—most importantly—learn to evaluate pearl quality with your own eyes rather than relying solely on grade labels.

Why There's No Universal Pearl Grading Standard

The diamond industry spent decades developing standardised grading through organisations like the Gemological Institute of America (GIA). Unfortunately, no equivalent standardisation exists for pearls. Several factors contribute to this:

  • Pearls are organic gems with more variables than mineral gemstones
  • Different pearl types (Akoya, freshwater, South Sea, Tahitian) have different characteristics
  • Cultural differences between Japanese, Chinese, Australian, and French Polynesian pearl industries
  • Historical lack of coordination between pearl-producing regions

The result is a somewhat chaotic grading landscape where savvy consumers need to understand multiple systems—and maintain healthy scepticism about grade claims.

The AAA-A Grading System

The most common system you'll encounter, particularly for Akoya and freshwater pearls, uses letter grades from AAA (highest) to A (lowest). Some sellers extend this with AA+ and A+ intermediate grades.

AAA Grade Pearls

The highest quality designation in this system. AAA pearls should exhibit:

  • Surface: 95% or more blemish-free (minor imperfections visible only under close inspection)
  • Lustre: Excellent—bright, sharp reflections visible on the surface
  • Shape: Round or near-round (spherical to the eye)
  • Nacre: Thick, with no visible nucleus or thin spots

AA+ Grade Pearls

Very high quality, with slight variations from AAA:

  • Surface: 90-95% blemish-free
  • Lustre: Very good to excellent
  • Shape: Round to near-round

AA Grade Pearls

Good quality suitable for everyday wear:

  • Surface: 80-90% blemish-free
  • Lustre: Good—visible reflections but not mirror-like
  • Shape: Near-round to slightly off-round

A+ and A Grade Pearls

Lower quality grades with more visible imperfections:

  • Surface: 70-80% (A+) or less than 70% (A) blemish-free
  • Lustre: Moderate—less defined reflections
  • Shape: May be visibly off-round or baroque
⚠️ Grade Inflation Alert

Be wary of "AAAA" or "gem grade" designations—these aren't part of any standard system and are often marketing terms. Legitimate high-end dealers typically use AAA as their top grade. Claims of grades above AAA should raise questions about the seller's credibility.

The Tahitian A-D Grading System

Tahitian pearls from French Polynesia use a government-regulated grading system where A is the highest grade (opposite to how you might expect). This system was established by the French Polynesian government to maintain quality standards for their pearl exports.

A Grade (Highest)

  • Surface imperfections on less than 10% of the pearl's surface
  • Excellent lustre with strong light reflection
  • Round or near-round shape

B Grade

  • Surface imperfections on less than 30% of the surface
  • Good lustre
  • Imperfections concentrated in one area (can be hidden in setting)

C Grade

  • Surface imperfections on less than 60% of the surface
  • Medium lustre
  • More visible blemishes

D Grade

  • Surface imperfections exceeding 60% of the surface
  • Lower lustre
  • Legal minimum for export (lower quality pearls cannot legally be exported from French Polynesia)
📋 System Comparison

Confusing but important: Tahitian A grade ≈ Akoya AAA grade (both are top quality). Don't confuse Tahitian "A" (excellent) with the AAA system's "A" (lower quality).

South Sea Pearl Grading

South Sea pearls, particularly those from Australia, often use a hybrid system or proprietary grading scales. Australian South Sea pearl producers typically grade on the AAA-A system, but some use descriptive terms:

  • Gem Quality: Equivalent to AAA—exceptional in all factors
  • Fine Quality: Equivalent to AA+-AA—very good but not perfect
  • Good Quality: Equivalent to A+—visible imperfections but good lustre
  • Commercial Quality: Lower grades suitable for less critical applications

Given South Sea pearls' high value, always request detailed information about the grading criteria used by the specific seller.

What Grades Can't Tell You

While grades provide useful shorthand, they have significant limitations:

Colour Isn't Graded

Pearl grades typically focus on lustre, surface, and shape—not colour. Two pearls of the same grade can have very different colours, and colour preference is highly personal. Golden South Sea pearls aren't necessarily "better" than white ones; they're simply different.

Size Isn't Graded

A 6mm AAA pearl and a 12mm AAA pearl have the same grade but vastly different values. Size is measured separately in millimetres.

Overall Beauty Is Subjective

Sometimes a technically lower-grade pearl has a unique beauty that surpasses "perfect" specimens. Baroque pearls with exceptional lustre can be more captivating than round pearls with lesser glow.

How to Evaluate Pearls Beyond Grades

Rather than relying solely on grade labels, learn to evaluate pearls yourself:

The Lustre Test

Look at the pearl's surface under good lighting. Can you see clear reflections? Can you see your own reflection in the pearl? High-quality lustre creates sharp, bright reflections—not fuzzy, diffuse light.

The Surface Inspection

Examine pearls closely (a jeweller's loupe helps). Note any bumps, pits, wrinkles, or discoloured spots. Consider whether these would be visible when worn—blemishes visible only under magnification are less concerning than those obvious to the naked eye.

The Roll Test

Roll the pearl on a flat surface. A truly round pearl rolls smoothly in a straight line. Off-round pearls wobble or roll in curved paths.

The Comparison Method

When possible, examine multiple pearls side by side. Differences in lustre and quality become much more apparent through direct comparison than when viewing pearls in isolation.

✨ Key Points to Remember
  • There is no universal pearl grading standard—systems vary by seller and pearl type
  • AAA is typically the highest grade in the AAA-A system (Akoya, freshwater)
  • A is the highest grade in the Tahitian A-D system
  • Be sceptical of grades above AAA—these are usually marketing terms
  • Grades don't account for colour, size, or subjective beauty
  • Trust your eyes: examine lustre, surface, and shape yourself
  • Buy from reputable sellers who explain their grading criteria

Making Informed Purchases

When shopping for pearls, ask sellers specific questions about their grading:

  • What grading system do you use?
  • What criteria determine each grade level?
  • Can you show me examples of different grades for comparison?
  • What is your return policy if I'm not satisfied with the quality?

Reputable sellers will answer these questions openly. Evasive or vague responses about grading should raise concerns.

Ultimately, the best approach combines understanding of grading systems with personal evaluation. Grades provide useful starting points, but your own assessment of a pearl's beauty and quality should guide your final decision.

Have questions about evaluating pearl quality? Our team is here to help.

SM

Sarah Mitchell

Founder & Pearl Specialist

Sarah is a certified gemologist with over 15 years of experience in the jewellery industry. She has personally graded thousands of pearls and is passionate about helping consumers understand quality assessment.