I wanted to create this for a while now and the topic "Prehistoric" seemed suitable, as you would normaly find already long extinct insets in these stones. Since time is short I did not put a fly or ant inside the amber, but it looks cool without it as well. The material is pretty basic and most things where done through shading inside Marmoset Toolbag

100% Substance Designer
Rendered in Marmoset
Texture Breakdown with Markus Pohl's "Texture Breakdown Tool"