In 2008, scientists from the Spanish Institute of Geology and Mining (IGME) discovered a huge amber deposit in the northern Spanish region of Cantabria (see Maria Najarro..., https://welt.de). The deposit, which was found in the cave of El Soplao west of Santander and has an age of about 110 million years, consists mainly of stones with a bluish-violet coloration. This colour is very rare and has been found mainly in the Dominican Republic. The El Soplao cave is also a real paradise for those interested in caves. A network of caves with spectacular stalactites and stalagmites amazes visitors. A mining train leads into the interior of the very extensive cave, from where you can continue on foot for longer distances.
Literature:
María NAJARRO, Enrique PEÑALVER, Ricardo PÉREZ‐DE LA FUENTE/Review of the El Soplao Amber Outcrop, Early Cretaceous of Cantabria, Spain, 23. August 2010, https://doi.org/10.1111/j.1755-6724.2010.00258.x
https://www.welt.de/wissenschaft/article2679404 /Groesstes-Bernstein-Vorkommen-in-Europa-entdeckt.html