From: Dictionary of American Naval Fighting Ships, Vol. II p 66

Chalcedony

A translucent variety of quartz, commonly pale blue or grey with a waxlike luster.

Chalcedony (PYC-16) was built in 1931 as Velero III by Craig Shipbuilding Co., Long Beach, Calif.; purchased from the University of Southern California 15 December 1941 ; converted at San Diego Marine Construction Co., San Diego, Calif.; and commissioned 27 February 1942, Lieutenant (junior grade) E. E. Smith, USNR, in command.

Chalcedony served in the 11th Naval District until 21 April 1942 when she sailed from San Diego for Pearl Harbor, arriving 1 May. She spent the remainder of the war under the command of Hawaiian Sea Frontier on weather station duty. Departing Pearl Harbor 5 November 1945, Chalcedony arrived at San Francisco 15 November. She was decommissioned there 10 January 1946 and delivered to the Maritime Commission for disposal 17 October 1946.