|Nacre is the iridescent layers which are
produced by the mollusk to coat the nucleus. Looking
through the drill hole of a pearl with a 10x loupe, or
twirling the pearl around to see how transparent the bead
is are ways of evaluating nacre thickness.
- Very thick: 0.5mm
(millimeter) of nacre, approximately 2 years of
cultivation. Can not see any nucleus with unaided
- Thick: .45mm of nacre,
approximately 1 ½ - 2 years of cultivation. Can
not see any nucleus with unaided eye
- Medium: .35mm of nacre,
approximately 1- 1 ½ years of cultivation.
Nucleus not visible with unaided eye
- Thin: .30mm of nacre,
approximately 9 months to 1 year of cultivation.
To the unaided eye the pearls appear to blink
- Very thin: .25mm of
nacre, approximately under 9 months cultivation.
To the unaided eye pearls have fisheye look,
nucleus lines are visible
||1 ½-2 years
||1- 1 ½ years
||9 months-1 year
||under 9 months