When Jane Perham decided it was time to close Perham’s Maine Mineral Store in 2009, the beloved institution her father founded in 1919, she worried about what would become of the collection of minerals and gems that her family had acquired over the decades.

“I prayed and suffered a long time about what I was going to do with it,” Ms. Perham said. “I knew I wasn’t going to break it up. That wasn’t going to happen no matter what.”

Then Lawrence Stifler and Mary McFadden expressed interest in purchasing the entire collection. The Perham legacy would be kept intact, and in Maine.

Mr. Stifler and Ms. McFadden, married philanthropists based in Massachusetts, have dedicated themselves to helping preserve western Maine’s rich mining history, of which the Perham store was an integral part. The material they received from Ms. Perham constitutes one of 10 major local collections of minerals, gems and rocks that the couple have acquired. Now those items form the cornerstone of the Maine Mineral & Gem Museum, located in the town of Bethel, which Mr. Stifler and Ms. McFadden opened to the public Dec. 12 after years of development.