Glass is one of the most versatile of all materials. Any shape, in any color, is possible for beads, pendants and rhinestone accents.
everydayhealth.com tells us that:
"There are several standard types you will find glass artisans crafting: Fused-glass jewelry– ...usually used in pendants and earrings and is considered to be a one-of-a-kind work of art. Also called art glass, these pieces are made by layering small cut pieces of colored glass together...put into a kiln and fired... After the glass has melted, or “fused” together, it ... can then be shaped and mounted into almost any setting.
Dichroic-glass jewelry – Made of pieces of sparkling, shimmering material, mounted onto clear or black glass. [It is] 50 micro-thin layers of different metals developed by NASA for astronauts’ facemasks to protect them from radiation. The colors of dichroic glass shift & meld together when fired, so these designs [flow].
Glass beads – These are tiny works of art that are strung together as bracelets or necklaces, or mounted into glass-jewelry rings and earrings. They are made with a process called lampwork, which uses a very hot torch to melt glass rods into any number of colorful patterns.
Murano glass – Also called “Venetian glass” or “millefiori,” this type of glasswork was developed centuries ago on an island off of Venice, Italy. The process of using the ends of glass rods to make many small flowers inside the glass (the term “millefiori” literally means “one thousand flowers”) makes this type of glass unique and easy to spot. Each piece must be made by hand, using a painstaking process, and true Murano glass pieces can be expensive. Because the glassmakers on the island of Murano have been working for centuries, you can find antique jewelry pieces of Murano glass – but educate yourself so you are not taken in by fakes.
Sea glass – Sea-glass jewelry (also called beach glass) has a loyal following of people who have an affinity with the sea. True sea glass is made when a broken piece of glass is thrown into the sea where it is tumbled and pounded by the sand and waves until it emerges smooth and opaque on the beach. "