Pearls are like fingerprints; each is unique. In 1974, Mikimoto established an industry standard with the first grading system in the U.S. for Akoya cultured pearls. Based on consumer demand, Mikimoto eventually adapted the system to grade South Sea cultured pearls.
While imitation systems exist, Mikimoto literally sets the standard for grading the quality of cultured pearls.
The Mikimoto pearl grading scale illustrates the system, with AAA representing the very highest quality.
Although no single factor can solely represent the worth of a pearl, luster and surface perfection are most important. Mikimoto graders spend years becoming experts in assessing these gems of the sea.
The Pearl Pyramid represents the quantity and quality of all cultured pearls harvested in Japan. Only the best cultured pearls are deemed worthy to carry the Mikimoto name.
|AAA||Exceptional, Mirror-Like Reflection||Blemish-Free Surface*|
|AA||Superb, Clear Reflection||Very Slightly Blemished|
|A+||Very Good, Clear Reflection||Very Slightly Blemished|
|A||Good, Clear Reflection||Very Slightly Blemished|
|A1||Good, Clear Reflection||Slightly Blemished|
* Tiny marks are part of the pearl's natural texture.