Live streaming video feed of Siesta Key Beach in Sarasota, Florida. Siesta Key's Siesta Beach has accumulated numerous awards in recognition of its soft, clean, pure-white sand. Consistently, it is rated among the top ten beaches of Florida, the U.S., and the world. Harvard University's geology department found the sand of Siesta Beach was 99% pure quartz. Unlike most beaches that are composed of crushed shells, rocks or lava, this sand is pure white and finer in texture than most refined sugar.