Amber is a beautiful Gem that comes in a variety of colors ranging from yellow, to green, and even some very rare blues. Amber is a Gem but not a Gemstone. Amber is not a mineral. When a tree is punctured it releases a sticky resin (note: not sap). The resins of these ancient trees are then hardened and fossilized through very specific conditions into what we now call Amber. 
Egyptians believed Amber to be the tears of the gods. Specifically the Sun god Ra. The beauty of Amber has been appreciated by mankind since the later part of the Stone Age, or Neolithic times.
Amber is a soft substance rating approximately 2.5-3 on the Mohs scale. Jewelry made of Amber should be worn with care to prevent damage.