Amber, simply put, is ancient tree sap that has turned to stone over time. Scientifically, amber is the resin of certain trees that has fossilised over millions of years. It is a light, organic substance that is usually yellow or orange in colour and often transparent. It is formed by trees exuding resin, usually through breaks or cuts in the bark. Once the resin is expelled, it hardens and drops to the ground. It is eventually buried in the dirt at the base of the tree and hardens further. Over the next few thousand years, this resin is called copal, which is still soft and essentially unfossilised. Copal is usually much younger in age than true amber, and is much less desirable to jewellery makers and collectors. Copal that is preserved in sandstone will eventually become amber over time – Copal that is preserved in clay will take much longer to fossilize. This transformation is called “amberization”, and is an ongoing process that takes millions of years. At this point, this inert resin is considered to be true fossilized amber.