Wendy, that was a lot of work! and Pragmatically, what you say is correct.
This is how Pearl-Guide defines hanadama:
-----hanadama: Highest quality portion of a cultured akoya pearl harvest.
This is how Pearl Paradise defines hanadama:
Hanadama Akoya pearls are the finest akoya pearls produced in the world today. After every pearl harvest in Japan, the pearls are separated into graded lots to be sold direct to processing factories or at live auctions. Of the separated lots, there is always one lot that is treated differently - these pearls are referred to in Japanese as hanadama akoya pearls. They are the pearls selected from the harvest due to their remarkable luster, surface and overall quality. These pearls are handled and sold as a separate product.
Much like diamond certification in the United States, before a strand or pair of hanadama akoya pearls can be marketed as hanadama, they must first go through laboratory testing in Japan. The most respected laboratory that conducts this test is known as the Pearl Science Laboratory of Japan. At the laboratory, technicians examine and grade the average nacre thickness, and they evaluate the luster and surface quality. A base minimum of excellence in each category is required to achieve the grading level of hanadama.
OK So we have a situation as if someone came over here and asked us about A, AA, and AAA gradings, stating that Ebay sellers use AAAAA+++++, so aren't their pearls better?
The answer is there is no legal standard for any grade of pearl, including hanadama, so it it up to the interpreter to define these grades for themselves.
Many reputable pearl sellers describe their akoya pearls from A-AAA and define what each grade means somewhere on their website. And the better sellers have higher, not lesser definition for the grades.
Originally, the definition of hanadama was reserved for the cream of the AAA grade, and is still how hanadama is defined on this site and on Pearl Pearl Paradise's site, so you will never get a grade AA pearl with a hanadama certificate from many sellers, though apparently you can from some others. Does that mean the definition of "Hanadama" includes the lower grades? Of course, not!
Just because some merchants call inferior grades AAA or AA+ or whatever, does not mean much unless you know their definition of the grade. Many sellers cheat on these grades or exploit them for sales. However, I would hold in disregard any seller that tries to sell you less than the top half of the AAA harvest as hanadama. They are using a word that was defined as the highest quality and are applying it to lesser qualities. Does that mean no one should use and define hanadama as the best, anymore?
No more than people should quit using the A-AAA scheme because some eBay sellers degrade their qualities in their own wares so as to seem as good as the wares of people who apply those grades. Just because one can get Hanadama certificates for any grade, apparently, as one can one get A-AAAAA in some schemes does not mean the definition has changed.
It means beware of sellers who do not hold to this standard. So what if some people grade those standards to make their own wares seem better? That does not make it correct or right.
It means look at how dealers define their grades and choose someone that has clear definitions and sticks by them.
What really gets me about this conversation is, I detest akoya pearls for many reasons. I detest most of the schlock that is sold out there because akoyas went through a stage where minimal nacre was fine and many still push thin skinned akoyas. Akoyas are barely barely dipped in the oyster, compared to any other type of cultured pearls. I will never wear one, I will never buy one. I will never sell one. I think they are the first gropings in pearl cultivation and all the standards have slipped, since my Mother in Law bought her first strand in the 1930's. I vastly prefer the solid nacre of the freshwater pearl and keshi from SS and Tahitians. The one exception I have to make is for cultured Sea of Cortez pearls. And their quality is strictly controlled by the owners.
So to sum up. Anyone who sells less than the top half of the AAA harvest as a hanadama is lowering the standard, adulterating it, but just because some do that is not reason to change the definition to meet the lower standards. It also means that people who want proof they have a minimum of .4 nacre, can get it, as pathetic as 4mm is.