there are places, (the baltic, and Santa Domingo come to mind) where there are vast deposits of amber. it can be mined, since it lies in seams inches to feet deep. these deposits are from forest of amber producing trees that were once common to the area. other sites have amber, but not in thick seams. many places in the world, you can find smaller deposits of amber, sometimes in chunks, or petrified globs. (nowday, amber with a insect is more valuable than clear amber, in the not so distant past, the opposite was true. )
In any case, when amber is 2 or 3 feet thick, it is possible to mine and shape it into any thing--including a rod. I have no idea why rod shapes where first made, but soon after they were, the properties of the same were discovered.
one of the russian czars had a whole room made of amber.. (the walls, the floor, all the furniture, were cover in, or made directly of amber. (it was in the hermatige i think) Rather shocking i think, especially if you dressed in fur!
