Amber is tree resin that fossilises over millions of years. During the process, the resin loses many of its volatile properties and – placed under intense pressure and temperatures – transforms into a solid, orange-coloured gemstone.
As tree resin starts off in a sticky, viscous state, today many amber deposits feature ancient life forms, like insects and reptiles, or plant foliage – most dating between 30-60 million years old. These organic inclusions are highly prized, both by palaeontologists – who can study long-extinct organisms – and jewellery makers.
Currently, the oldest discovered amber dates from the Upper Carboniferous period, roughly 320 million years ago. This age is rare, however, and the majority of resin extracted dates from the Early Cretaceous or later. Most amber found today is thought to stem from the Sciadopityaceae family of conifer trees that were once prolific throughout Europe.