How do I tell an Orb from dust?

adjusted light and enlarged to see pattern on dust

original, please click on picture to be taken to original and larger version.

This is only the small version, as I encourage following through to the site.

The guy that took the pic kicked up some dust and took a picture for a reference point.
GREAT IDEA!

There are many comments under the picture but I like this one best:

From what I have always been lead to believe, dust usually has rings or lines in it (like the ones you see in the photo) whereas Orbs are usually colored, bright and often solid. Of course, there have been arguments for years on this subject, haven't there?LOL!

To me, I generally take the feeling I have, also into consideration when capturing, and also, from general observations, that when it is dust or rain or fog, there are generally a whole lot around (when taken with a flash), where singular ones, or orbs taken without flash..which really means they they light themselves....

Either way I thought this was good reference material :)