Jessica Vincent had just started surveying the shelves of a Virginia thrift store when a vase caught her eye. It was shaped like a bottle and had ribbons of color, aqua green and amethyst purple, that spiraled up its glass surface like stripes of paint. The piece looked old amongst the clutter of measuring cups, candles and other tchotchkes. After adjusting her eyes, Vincent made out the words “Murano” and “Italia" on its base. “I bought it thinking it would look beautiful in my house somewhere,” said Vincent, 43, a horse trainer who paid $3.99 at a Goodwill outside of...