Amber is made of prehistoric fossilized resin. It's a mineral fossil, it may look clear and trasparent or turbid, in some rare cases it may be fluoresent. It's color can be yellow, orange, reddish brown, very rarely it can be fluorescent green, blue or purple.
You can recognize real amber from imitations by inserting it in a container full of a saturated solution of water and salt, the real amber floats, the imitation doesn't. A most famous Amber stones are the ones that come from the Baltic, the Dominican Republic and Mexico.
The rarest Amber is called “Simetite” and comes from Sicily.
The things you can obtain by working amber are: strands of necklaces, flowers, animal shapes, other various shapes of things, perfume bottles and whatever the customer requests.