This is a lovely, vintage pair of clear rhinestone earrings likely dating between the 1920s and early 1950s.  The elegant earrings are made to resemble diamonds in a floral, Art Nouveau design.  The backing is screw back, clip style (see photos).  I am unable to find a maker mark and don't know what the metal composition is but do not see a mark indicating silver.  Best guess on a date would be 1940s as the back and style were popular during that time frame.  I purchased the earrings over 35 years ago in an antique shop.  The antique rhinestone jewelry is in nice condition, with all rhinestones in place and screw back freely turning.  The earrings measure about 1" x 1". Box in photo not included.