From: Dictionary of American Naval Fighting Ships, Vol.V p 162
A semi-precious stone: translucent quartz in parallel layersof different shades of color.
Onyx (PYc--5), a diesel yacht, was built in 1924 as Pegasus Consolidated Shipbuilding Corp., Morris Heights, NY; purchased by the Navy 3 December 1940 from Clifford C. Hemphill, of New York City; converted to Navy use and named Onyx; classified as a coastal yacht 13 December 1940 and commissioned 27 February 1941.
After conversion she departed New York for Norfolk, arriving on 22 March. Sailing again, she reached New Orleans 5 April to report for duty to Commandant 8th Naval District. Onyx performed services for ComEight as a coastal patrol vessel around the Gulf area until January 1942. On 22 January she departed Key West, Fla. to return to New York and arrived there 31 January.
Onyx was again ordered to report to the 8th Naval District at New Orleans and was underway by 13 March, arriving on 27 March. She resumed services and continued in this capacity until February of 1944 when she was extensively damaged in a collision. Beyond economic repair, her ordnance was removed and she was placed out of commission, in service, retaining her name and designation, 15 May 1944. She was designated a target vessel 31 May, the same year, and made available for disposition 31 October.
Considered for conversion to a fuel barge in November, her conversion never materialized and Onyx was placed out of service 1 February 1945 and returned to WSA 2 February. She was struck from the U. S. Naval Register 5 February 1945.