It’s a cool story, but the article is a bit messy.

Took me a while to understand what happened around 1990 and what happened recently.

I was also surprised to learn that El País employs time travellers:

In addition, the protected area contains the old Stramba amber mine, known as one of the most productive during the first half of the 21st century, but which was closed down by the communist regime as it was considered unprofitable.

I wonder if tree sap can be put through a process to immitate this like the artificial diamonds.