The Sardonyx was originally a steel-hulled yacht with diesel engines, built in 1928 as the Queen Anne for Mr. Alexander Dallas Thayer at the Germania-Werft shipyards in Kiel, Germany. According to United States Government publications from 1941, the USS Sardonyx was the sister ship to the USS Opal (PYc-8), formerly Irving T. Bush's and Marian Spore Bush's motor yacht Coronet; both yachts were built at the same yard in 1928.

The vessel was purchased by the Navy from the original owner at New York on 19 June 1941. Immediately after acquiring the yacht, the Navy started converting the vessel for use as a coastal patrol boat. On 18 July 1941, the vessel was renamed Sardonyx, and on 15 August 1941, it was commissioned. Conversion was completed by mid-October 1941, and Sardonyx proceeded for duty to New London, under the National Defense Research Committee (NDRC). Sardonyx served 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 1946, Sardonyx 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.

• List of patrol vessels of the United States Navy

• NavSource Online's article on Sardonyx
• More on the Sardonyx's original owner, Alexander Dallas Thayer
• This article incorporates text from the public domain Dictionary of American Naval Fighting Ships. The entry can be found here.