Some rare sapphires exhibit a color change under varying lighting conditions. Color change sapphires are typically blue in natural light and purple under incandescent indoor light. Color changes may also be pink in daylight to greenish under fluorescent light. Some stones shift color well and others only partially, in that some stones go from blue to bluish purple.
I make wire wrapped pendants for birthday presents, and always feature a birthstone as the base for the project. GemSelect has a wide variety of shape/size pieces to fit any budget. A detailed description of each individual stone is perfect for those searching for particular stones for their application, and information on stone treatments and the like are phenomenal.