We went to the Amber museum on part of a half day tour of Puerto Plata.
The museum itself is basically one floor of different specimens of amber and blue amber with fossils in them. It was interesting to look at it but didn't take very long to get through. The downstairs area has a few rooms with various items for sale, including amber and turquoise jewelry as well as rum and cigars. If you're going to buy amber, do it here as their jewelry is guaranteed to be authentic. A lot of times, people will sell what looks like amber and it is only colored plastic so you do need to be careful. I got a beautiful silver and amber ring for only $12 U.S. They also had earrings, necklaces, bracelets, and rocks of amber for your home.