Natural resin sources - ideas for a hard resinous substance?

I want to make some art that will be an object in a resin.  Like an insect trapped in amber - that sort of thing.  I'd like to make some of them kind of large, maybe 3 inches cubed in volume?  

What resins do people know of that will harden in a reasonable amount of time?

Any thoughts or experiences using resins?  I don't want to use epoxy resin...I'm looking for a natural substance.

Thank you!

I sometimes see resin that forms on cherry trees.

I observe resin often times oozing out of conifers.

If the objects are heat resistant, glass would be an option. Or maybe a hollow glass container filled with some kind of oil with similar refractive properties. I tried to work with resin from cherry trees once. It took very long to cure and did not stay clear, but i did no research at all, so there probably is a way to make it work better.

Gum Arabic perhaps, it can be melted and reshapped.

I think most pitch from pine/fir trees can be boiled down so that it will harden quicker.

If you know any bee keepers perhaps you can get some propolis.

Hmmm... Thanks for the ideas, I hadn't thought of those.  Shellac is the closest thing I've found to what I'm looking for.  I'm not in a region where I could tap or nab resin from trees right now.  I think I'm going to have to buy something.

Beeswax has also come to mind.  I wish there was some way to make it a little more durable. Like harden it so it won't easily scratch.  

Has anyone had experience using shellac?

Thanks for everyone's thoughts!