New Almaden hydrothermal deposition of cinnabar from deep within the earth is found in a gangue of silica-carbonate rock formed locally by hydrothermal alteration of serpentine. The Guadalupe mine produced about 10% as much mercury as the New Almaden. There are several smaller mines in the mining district, but their ore production was not significant. The only significant quicksilver ore is cinnabar; other sulfides are present in small quantities. Mining, other than a single placer deposit of cinnabar, was underground. There is a high probability of undiscovered high-grade ore which could be found and exploited using modern techniques. Mining operations resulted in
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