Rock crystal - or clear quartz - is colorless and transparent or translucent, and has often been used for hard stone carvings. Art Deco jewelry designers in the late 1920s and 1930s frequently used rock crystal set or accented with diamonds to form bold and eye-catching pieces. Occasionally a brightly colored stone such as coral, jade or onyx would also be added to the jewel.

For those who could not afford the stunning look of rock crystal with diamond and platinum settings, an imitative material, camphor glass, was used in less expensive jewelry. This clear glass was treated with hydrofluoric acid vapors to create a frosted whitish finish and was often cast with a star pattern on the reverse side to provide a radiant appearance.

Camphor glass from the early 20th century Edwardian period is often found set in pendants and bracelets. Edged in silver or other white metals they often have a diamond, diamond “look alike” or a sapphire or other blue stone set into the middle of a glass panel.