This is Glass Beach, in Fort Bragg, California, one of the most unique beaches in the world - unique not because of nature, but because time and the pounding surf have corrected one of man's many mistakes. Beginning in 1949, the Glass Beach area became a public DUMP. People dumped all kinds of refuse straight into the ocean, including cars and household garbage. The household garbage, of course, contained a lot of glass. By the early sixties, some attempts were made to control what was dumped and dumping of toxic items was banned. In 1967, the North Coast Water Quality Board realized what a screwed-up situation this was and plans were begun for a new dump away from the ocean. Over forty years later, Mother Nature has reclaimed this beach. Years of pounding wave action have deposited tons of polished glass at this beach. Please see here.
The California State Park system controls the area now and glass is not allowed to be taken, not that that would stop Rosie. In other words, you can't take away their garbage.
Beach glass is pretty. Check it out here.