[Rockhounds] Off Topic Geology in Progress

[Axel Emmermann]

Earl wrote

>It was too much like taking out a mortgage on a school of herring."

[Axel] I had no idea that it took a degree to be a herring. I once heard
that sending fish to an exclusive and expensive private school of herring
could turn them into turbot... Any truth in that? ;-))))

Seriously, could a vertical upward flow of water be used to separate
different minerals according to size or smoothness? 
Or separate grains of minerals from the gangue?

Perhaps this has been suggested already but I' ve been too busy to do much
rockhounds debating the last week ;-)

Cheers
Axel