The Pearl Button Allende to rehabilitate the surviving tribespeople; the concentration camps set up under Pinochet; how inmates were tortured and how their bodies, weighted with lengths of rail, were dropped from helicopters into the Pacific; how one corpse was washed ashore; and finally how one of the lengths of rail recovered from the sea had a mother-of-pearl shirt button encrusted to it. The Pearl Button The Pearl Button () is a 2015 Chilean documentary film directed by Patricio Guzmán. It was screened in the main competition section of the 65th Berlin International Film Festival where it won the Silver Bear for Best
Pearl extensive and successful use of the Biwa Pearl Mussel is reflected in the name "Biwa pearls", a phrase which was at one time nearly synonymous with freshwater pearls in general. Since the time of peak production in 1971, when Biwa pearl farmers produced six tons of cultured pearls, pollution has caused the virtual extinction of the industry. Japanese pearl farmers recently cultured a hybrid pearl mussel – a cross between Biwa Pearl Mussels and a closely related species from China, "Hyriopsis cumingi", in Lake Kasumigaura. This industry has also nearly ceased production, due to pollution. Japanese pearl producers also invested