Naut. [perh. a sailors’ fanciful appellation.] The name given to each of two small blocks suspended at the extremities of the main and fore-topsail yards, through which the halyards of the studding-sails are passed.
1769–89. Falconer, Dict. Marine, s.v., The haliards, by which those studding-sails are hoisted, are accordingly passed through the jewel-blocks.
c. 1860. H. Stuart, Seaman’s Catech., 19. Jewel blocks, are not on royal yards, unless royal studding sails are used.
