Green’s Dictionary of Slang

1. a moment, a very brief period of time; usu. as in a twink, in a very short time.

1611		Shakespeare Tempest IV i: ari.: Presently? pro.: Ay with a twink. ari.: Before you can say ‘Come,’ and ‘Go.’.
1681		Otway Soldier’s Fortune IV iii: I’ll only bolt the door [...] that he may be safe, and be with you in a twinkle.
1772		Bridges Burlesque Homer (3rd edn) 540: Go drub yon’ lousy rogues, and then / We’ll in a twink be back again.
1794		W. Godwin Caleb Williams (1966) 235: And he made a hell of a rumpus and sent away Kit to prison in a twinky.
1798		‘Peter Pindar’ ‘Tales of Hoy’ Works (1801) V 264: He never wanted news at a pinch; would spring from Dan to Bersheba in a twink.
1865		Leaves from Diary of Celebrated Burglar 18/1: In a twinkle someone tuned off the gas.
1884		‘Career of a Scapegrace’ in Leicester Chron. 10 May 12/1: If you aren’t off in a twink I’ll half drown you.
1890		Bulletin (Sydney) 5 July 6/1: The fashionable trouser is an uncanny thing [...], and any clever young man who owns a thimble and a packing needle could make himself a pair of fashionable continuations in two twinkles.
1895		Truth (Sydney) 5 May 6/1: Harry Raynor threw the colt and tied him up in a twinkle.

2. (US) a diamond ring.

1903

Inter Ocean (Chicago) 25 Jan. 34/4: I was just $1,200 on the blut — $700 in the yellow papers, a $300 third-finger twink, and a $200 search-glim.