Amber

Batic amber is sap from ancient conifer trees. It has been fossilized but not mineralized. This sap is sticky at first, attracting insects and other small critters along with plant life and sticks. Most of these things end up rotted away except for some of the insect exoskeletons. Meaning most of the items are just casts in the amber. Butter Amber is the sap with traped tree pollin. About 90% of the world's extractable amber is in the Kaliningrad region of Russia on the Baltic Sea.