[jshepherd]

The Hanadama certificate can only be produced by a lab in Japan. We personally use the Pearl Science Laboratory in Tokyo (sinjuken.co.jp).
The pearls are examined by the following methods:

Magnification
Inner Inspection by Optical Fiber
Spectro Photometric Reflectance
Soft X-ray

The thickness of the pearl layers are measured. Although it is stated on another well-known Site that the thickness must measure .6 on either side for a total of 1.2, the actual requirement is .4 for a total of .8. (this is determined by the optical fiber and soft X-ray apparatus).

The Teri-value (luster) must be strong.
The kizu (imperfection) must be listed as very slightly. It is important to note that 'very slightly' is the highest allowable 'kizu' grade by the lab.

If the factors are all graded high, the strand receives the grade 'Hanadama' by the lab. This is a term reserved for the highest quality Akoya pearl strands. The term is only reserved for Akoya pearls. Hanadama is the grade of pearl that Mikimoto carries for their highest quality line.

Hanadama strands are difficult to carry in large quantity. We currently only have approximately 20 strands with Hanadama certificates in stock. The range in size from 7.5-8mm up to 8.5-9mm. So far this year we have not received any Hanadama strands larger than 9mm. We had about a half dozen last year, however.