dichroic cristallo beadmaking Barovier goldstone smalt nyn Suhag punty panes GeO2 chintzes gorgonzola stemware Photochromic vaseline Annealed microballoons cullet Raschig vinylester magnifying Holophane Pyrex devitrification millefiori pontil opalescent Photosensitive Lipofsky opaline ranita phosphors germania GeCl4 PbO annealed Favrile