subs. (thieves’).—A doctored diamond or other precious stone. Cf., TRIPLET. [The quots. show derivation.]
1706. E. COLES, English Dictionary. DOUBLET, a precious stone of two pieces joined.
1822. SCOTT, The Fortunes of Nigel, ch. xxxi. Your een are sharp enough to look after gowd and silver, gems, rubies, and the like of that … Look at them—they are a’right and tight, sound and round, not a DOUBLET crept in amongst them.
1877. W. H. THOMSON, Five Years’ Penal Servitude, iv. 273. Most jewellers and pawnbrokers are well acquainted with what are called ‘DOUBLETS.’ These are rubies or emeralds made of two pieces. The face is a real ruby, emerald, or sapphire, as the case may be, and this is backed up by a piece of coloured glass.
