What is a formal ball for debutantes called?

A prong-style setting for diamonds introduced in 1886 is named for which New York jewelry store? In grammar, which form of a word, abbreviated "dim.", indicates smallness, as in "duckling"? What does IUD, a form of birth control, stand for? Solid, liquid and gas are each a what of matter? What kind of formal public statement did Abraham Lincoln issue on January 1, 1863? What is a formal reduction in rank, status or position called? A formation known as Half Dome rises more than 4,700 feet above the valley floor in which California national park? What did the former European nation known as the GDR call itself in English?