What is the difference between crystal and glass rhinestones?

Rhinestones are generally made of crystals but some Rhinestones are made of glass or acrylic. Rrhinestone has a foil or metal backing that reflects light and gives the stone more glitter. On the other hand, crystals do not have any foil or metal backing.

Crystals are solids that have ions, atoms and molecules arranged in a regular way, which extend in three dimensions. Rhinestones are generally made of crystals but some Rhinestones are made of glass or acrylic. Rhinestone has a foil or metal backing that reflects light and gives the stone more glitter.The Story of Rhinestones

Once upon a time in the 13th century, rhinestones were made of small, sparkling pieces of quartz found in the Rhine River in Austria and cut to resemble precious gemstones like diamonds. As with all good, beautiful things coveted by the masses, supplies dwindled, leading to imitations made out of paste – glass powder, melted, molded, and formed into dense glass stones. Fast forward a few hundred years to today’s rhinestones, which are now offered in many options: Mass-produced gems created from a variety of qualities of materials, from acrylic and plastic to glass and crystal varieties, such as those by Swarovski.