There are several "tests" that identify amber. They can distinguish it from the confusing mimics. The first I would try is to determine its relative weight, This is easy, amber will float in salt water. Trying this will rule out a translucent mineral. Rub it on a wool item. Does it develop a static charge (e,g, attract small bits of tissue)? Amber will. Next, apply a small drop of acetone (fingernail polish remover, check the ingredients). Let it evaporate and press a piece of tissue on the spot