In costume jewelry, glass is an umbrella term covering everything from beads to crystals to rhinestones. Though it is most often associated with beads, the material’s roots go back to the Victorian Era, when glass was used as a substitute for diamonds. Throughout much of the 19th century, Vauxhall glass—which can be clear, colored, or backed with mirror—was fastened onto pins and earrings. In the 20th century, Italian glass beads from...Continue Reading