What is this?

This looks like amber to me, and I guess in a remote way ,it is. Amber is petrified tree resin (not sap) that often has insect or other kinds of inclusions in it. The better the inclusions, the more expensive . Real amber comes from deposits in the baltics, Russia, Dominican Republic, and some low grade stuff from Kansas and New Jersey.
The origin of this is Gold Hill Alabama. I had a plum tree die. Well, actually half of it was dead and I got it cut down as it never made any plums after the first 3 years. It had a 'mummy' disease and the plums were no good. These pictures taken after the surgery, show the leaking sap from the living part of the tree. The darker blobs may be from a borer that killed half the tree. Or not? What do you think?