I used to sell marbles on eBay – I still have many fine examples
My method to get the best pictures was using pure daylight and a good digital camera. I would use a stick attached to one end of a desk by a window ensuring the window had only sky as it's view - I would then stick the marble (they are not heavy, even the 1.5" diam ones) on the end of the stick with a tiny piece of white-tack. I would align the camera using books to get the correct height for a dead shot, no flash - macro on modern cameras allows for infinite detail.
Morning or late afternoon skies give best results (on a clear day of course)
German marbles 1860s - 1920s were my best sellers
Latticinio Core Swirl
Two layer Latticinio Core Swirl
Divided Core Swirl
Solid Core Swirl
Ribbon Core (only the older kind)
Onionskin (if by a good maker can be worth lots)
There are many more like 'Peppermint Swirl' and 'Clambroth'
The best maker I could hope for was ‘Lutz’ - containing aventurine and made to perfection
Price wise I always got about a third of any book price
American marbles were less hot, they are not as old as German ones, but some 1920s ‘Christensen Agate’ marbles are valued at £250.00 – mostly I got ‘Akro’ or ‘Peltier’
Collectors don't like nasty chips but a few nicks here and there is a sign of age as is the roughly ground patch at each end of the core (showing manufacture) - older marbles are never perfectly round - that came later 1920s 30s onwards with machine made marbles
I sold to some very knowledgeable guys. It was a while ago but I can always invite them to the board :?:
Adam P