Swarovski crystal beads are also prized by jewelers and hobbyists. They are a content high-lead crystal although today production of lead-free crystal is common. Crystals have an incredible sparkle and clarity, and are often multi-faceted to resemble gemstones. Styles and colors go in and out of production, so vintage cuts and colors are often prized with a similarly associated price tag. Swarovski bicones are the most popular crystal beads in sizes 4mm and 6mm with crystal and crystal ab as the most common colors. Czech companies such as Preciosa® and others make similar styles of crystal beads.