Pearl Grading Standards

Background

The Tahitian pearl (or black pearl) is an organic gem formed from the black lip oyster (Pinctada margaritifera).The pearls are primarily cultivated in French Polynesia, around Tahiti.

Tahitian pearls are among the rarest and most valuable of pearls and have been called the ‘Queen of Pearls’. Because of their dark hues, Tahitian pearls are commonly known as ‘black pearls’. However, pearls are very rarely dark black and come in a range of various undertones and overtones of green, pink, blue, silver and yellow. The most desirable of these are of the darker variety, such as peacock green The oyster inside of which they grow is quite large, and Tahitian pearl are generally 9.00 mm to 15.0 mm in size. The Tahitian pearl comes in different shapes including round, semi-round, button, circle, oval, teardrop, semi-baroque and baroque.

Pearl Grading

The Ministére de la Perliculture of French Polynesia has official pearl grading standards.

  • Top Gem: A perfect pearl with an excellent luster.
  • Grade A: A pearl’s surface must be without imperfections on 90% with very beautiful luster.
  • Grade B: The pearl must have a smooth surface on 70% with good luster at minimum.
  • Grade C: Smooth surface on 40%. Medium luster at minimum.
  • Grade D: Weak luster, Small imperfections on more than 60%.
  • Any pearls lower than D are not allowed to be exported.

Shape

  • Round pearls are most valuable and must be an almost perfect sphere with less than 2% variation in diameter measurements. Round and minimum surface imperfection are very rare.
  • Semi-round pearls have variations in diameter of greater than 2%, but less than 5%, so are slightly imperfect. Semi-round pearl can be purchased for much less than round pearls.
  • Semi-baroque pearls are grouped into 4 shapes: oval, pear, drop and button and have at least 1 axis of rotation.
  • Baroque pearls have no axis of rotation and are much less expensive.
  • Ringed or circle pearls have an axis of rotation and exhibit regular rings, streaks or grooves that are perpendicular to the axis. Typically, ‘ringed pearls’ are 25% to 30% of a pearl farm harvest.

Nacre thickness

More than 80% of the pearl’s surface must be coated with a continuous pearly layer (called nacre). Black pearls should have a thick or very thick coating of nacre.

Luster

Luster is the sheen that reflects light from the pearl’s surface. If light reflection is bright and sharp the luster is considered high or very high. If the light reflection is poor the luster is dull. Similar to color the luster of Tahiti pearls is natural.

Size

Compared to Akoya cultured pearls, Tahitian pearls are very large. Most sizes range from 8.00 mm to 15.0 mm. Larger size pearls are considerably more expensive than smaller ones.

Approximate Retail Prices for Single Grade AAA Tahitian Black Pearl

Size: 

8.0 – 8.9 mm  9.0 – 9.9 mm  10.0 – 10.9 mm  11.0 – 11.9 mm  12.0 – 12.9 mm  13.0 – 13.9 mm  14.0 – 14.9 mm  15.0 – 15.9 mm 

Price: 

$590.00 $790.00 $890.00 $990.00 $1290.00 $1590.00 $1990.00 $2490.00

IMPORTANT

There is a difference between Tahitian black pearls and other black pearls!

Both Akoya (salt water) cultured pearls and fresh water pearls are artificially black. These pearls are dyed or irradiated black to simulate the look of authentic Tahitian black pearls. The dye process saturates the nacre and strips the iridescence often leaving a uniform color and plastic-looking surface.

Authentic Tahitian black pearls are NOT dyed and have original colors meaning surfaces shimmer with deep, intense rainbow hues with iridescence and display a beautiful, natural luster.

OUR PEARL GRADING CRITERIA

There is no international standard for grading pearls. One supplier’s AA grade may be another’s A or AAA. To represent the standard factors of pearl grading (luster, nacre thickness, surface perfection, color, shape, size), the Pearl Amor grading system categorizes six important factors by three individual grade labels. Along with the three major categories (AAA, AA, A) there are also two sub grades (AA+, A+), wherein the + represents a slightly less blemished surface.

Tahitian Island Pearls AAA Pearl Grade:

Our Tahitian Island Pearls are graded to strict standards to assure you of quality.

  • Luster: High/Intense with an exceptional mirror-like quality.
  • Nacre Thickness: Very thick.
  • Surface Quality: Clean and virtually flawless, 98%+ blemish free.
  • Color: Varied colors with sharp and distinct overtones. Various shades of color are created by the refraction of light as it passes through the pearl layers. The body color is enhanced by at least one overtone. Tahitian pearls considered most desirable have a peacock green overtone.
  • Shape: Perfectly round.
  • Size: Varied, typically 8.0mm to 15.0mm.

Each item is also available with a Summation Of Appraisal certificate from the International Gemological Institute (IGI). This is to certify that the item described above is genuine, and has been independently examined in the laboratories of IGI and includes an insurance replacement value.

EIGHT QUESTIONS TO ASK BEFORE YOU BUY TAHITIAN PEARLS

  1. Origin: The Tahitian pearl is an organic gem formed from the black lip oyster (Pinctada margaritifera) and are primarily cultivated in the islands of French Polynesia, around Tahiti. Are the pearls authentic Tahitian pearls?
  2. Grade: Be sure it is graded according to the official classification developed by the Ministére de la Perliculture of the Polynesian Government. The highest grades are A and Top Gem.
  3. Value: Value is determined by size (usually 8.0 mm up to 15.0 mm), shape (”roundness”), lustre and surface quality rather than colour.
  4. Color: Tahitian pearls are identified as “black”, but are actually charcoal grey, silver, or dark green. The color peacock green is considered most desirable.
  5. Mounting: Highest quality pearls are set in 18K or platinum with VS or VVS quality diamonds.
  6. Price: For assurance, obtain an independent appraisal from an organization, such as the International Gemological Institute (”IGI”).
  7. Hype: Avoid exaggerated claims, such as 50%, 75% or more off of retail prices. Whose retail price?
  8. Other: Do pendants come with a chain? What quality gold, chain width and type of clasp? We include 18K gold chains with pendants to give you a total price.

We provide you with the highest quality pearl jewelry with full disclosure of pearl grade at a reasonable price.