Mercury (element) long periods at elevated temperatures. It reverts to the elements upon heating near 400 °C, as was demonstrated by Joseph Priestley in an early synthesis of pure oxygen. Hydroxides of mercury are poorly characterized, as they are for its neighbors gold and silver. Being a soft metal, mercury forms very stable derivatives with the heavier chalcogens. Preeminent is mercury(II) sulfide, HgS, which occurs in nature as the ore cinnabar and is the brilliant pigment vermillion. Like ZnS, HgS crystallizes in two forms, the reddish cubic form and the black zinc blende form. The latter sometimes occurs naturally as metacinnabar. Mercury(II)
USS Cinnabar (IX-163) USS Cinnabar (IX-163) USS "Cinnabar" (IX-163), a designated an unclassified miscellaneous vessel, was the only ship of the United States Navy to be named for cinnabar. Her keel was laid down in 1944. She was acquired on a loan-charter basis from the War Shipping Administration and placed in service at San Francisco, California, on 26 September 1944. She was assigned to the Pacific Fleet, and in November 1944 departed the West Coast in tow for Pearl Harbor. With Service Squadron 8, and later Service Squadron 10, she issued general stores to advanced bases at Eniwetok, Espiritu Santo, Ulithi, Leyte, and