An onyx of alternating layers of white and orange red chalcedony.
(PYc-12: dp. 640; l. 186'; b. 27'; dr. 10'6" (mean); s. 12.5 k.; a. 4 mg., 2 dct.)
Sardonyx (PYc-12) (ex-Queen Anne), a steel, diesel engine yacht built in 1928 by Germania-Werft, Kiel, Germany, was purchased by the Navy at New York on 19 June 1941 from Mr. Alexander D. Thayer, Miami, Fla. Commencing conversion immediately, she was renamed Sardonyx on 18 July 1941 and was commissioned on 15 August 1941. Conversion, to a coastal patrol yacht, was completed in mid-October, and Sardonyx proceeded to New London for duty, under the National Defense Research Committee (NDRC), in support of experiments on the varied applications of electronics and underwater sound to naval warfare.
In January 1942, Sardonyx shifted back to New York; but, after a brief yard period, she returned to New London and resumed her work for the NDRC and the Navy's Underwater Sound Laboratory. Decommissioned and placed in service on 3 January 1944, she remained based at New London, conducting operations for the Underwater Sound Laboratory and escorting submarines in the area, through the end of World War II and into 1946. In the spring of that year, she was ordered inactivated; and, with the summer, she moved to New York, where she was placed out of service on 17 July 1946. Her name was struck from the Navy list on 29 October 1946; and, on 10 July 1947, she was transferred to the Maritime Commission and sold.