Hi Airdancer,
I am very sorry to hear that about your Freshadamas but the Akoyas as well seem to lose their luster. I have pearls of all kinds so I can rotate them often, so far I have only noticed that some of my studs get dull where the pearls come into contact with my ear, so probably this is very unfortunate, you could have some agressive bodyoils (or chemical make-up) and in combination with the aircondition, which might account for drying out your pearls, this is the result. That is no expert opinion just my own thoughts. I believe that only really untreated pearls might be able to keep their natural luster but as practically all pearls are treated in some way (polished, bleached), it just happens sooner or later. And I am worried that the more luster treatment pearls get, the more they will lose it.
When cleaning them you should always give the pearls some humidity back so you at least can slow down the process. Perhaps you also can help the situation by trying to wear tops, where the pearls come into physical contact with the fabric rather than your skin.
It is a pity if you just havenīt enough pearl necklaces to change them on a regular basis. But I am sure this will be changed in the future, when you can afford to buy some more necklaces. As I said, I have this problem with my stud earrings. Akoyas probably will lose their luster even more fast as their nacre is much too thin to stand up to dryness, chemical things and so on. I also do believe (have no scientific proof though), that the quality of each harvest a certein given year might have something to do with it, perhaps the mollusks health does change the normal conditions for the pearls and it is not necessarily that the farmers/factory even can see this until the customers much later start to complain about luck of luster or other things
