Rhinestone Rectangular Brooch c1900 Rectangular brooch circa 1900 set with 20 large and 32 smaller rhinestones on a brass mount decorated with fine tooth edging. This timeless style would lend itself to an outfit of the period, or would set off an Art Deco or 60s outfit perfectly. The brooch measures 1 5/8" wide and 1 1/8" deep Originally, rhinestones were rock crystals gathered from the river Rhine. The availability was greatly increased when around 1775 the Alsatian jeweller Georg Friedrich Strass had the idea to imitate diamonds by coating the lower side of glass with metal powder. Hence, rhinestones are called Strass in many European languages. Rhinestones may be used as imitations of diamonds, and some manufacturers even manage to reproduce the glistening effect real diamonds have in the sun.