It's not enought a great job
... When I'll work high grades' pearls without loose any light, it will be...
As you suggest it, Katbran, my work allow to use flaws in final design, but any flaws are not good to do that, and the best would be to choise each pearl in my hand, not viewed on a computer.
For exemple, fireballs have thick nacre on the "tail", and often too much thin around the nucleus, but it's the opposite for many over baroque pearls: nacre is thiner on the sharp parts ! An over observation about lavander pearls : my tests to work them have shown that several are white pearls reintroduced, for a short time, in different shellfishs than the first where pearl was born. Carving these lavander pearls, I have found, under a very very thin layer of lavander nacre, a thick layer of yellow conchiolin, not right to go on my work. I think it's the result of this transfer I suspect. Anyway, an unexpected difficulty again... Just a small lavander biwa pearl has been enought homogeneous to be carved.
The conclusion is that farmer's working to make nice pearl is maybe (sometimes or often ?) just take action on the last appearence.
Now, I'm sure I can give a good design, uncommon, even to round pearls. I have not yet bought, as irregular shapes I prefer too, and what I am looking for, suitable for my work, on the net.