Написал Дэвиду Джойсу, вот что он дословно ответил:
"Dear Anatoly,
Yes, I know EXACTLY how the rings formed like this. It is elementary. God made them this way as a joke on us!
Many people have wondered at these rings and tubes. I have always assumed that they were formed this way as a result of a repeating offset in the crystal structure when the boulangerite was crystallizing. (like twisted crystals) That is a very superficial assumption, though since I do not even know the configuration of a unit cell of a boulangerite crystal. I think there must be an eminent scientist, somewhere, that can undertake more educated assumptions and conclusions on this theory.
Some people have thought that the rings formed around the base of hydrocarbon droplets since these droplets are often present in the Rogers Mine fluorite veins. I do not like this theory at all, since they do not really look like they formed around a hemispherical droplet and it does not explain suspended rings or cylinders!..."
Собственно, он в сжатой форме воспроизводит две из версий, содержащихся в статье Ричарда Бидо. Завтра постараюсь на работе отсканировать ее и выложить. Статья весьма интересная, но точного ответа на вопрос, как все происходит, и она не дает - только теории.
Видимо, прав Дейв, нужен выдающийся ученый ("eminent scientist"), чтобы в этом досконально разобраться.
