Green’s Dictionary of Slang

1. one who steals jewellery or precious stones or metals, esp. by entering a shop, asking to inspect the stock and, using an adhesive substance on their hands, picking up certain items; thus pennyweighting, pennyweight job, performing this variety of theft.

1880		Colfax Chron. (Grant Parish, LA) 21 Aug. 2/3: ‘What is a pennyweighter?’ was asked [...] ‘I’ll tell you. the racket is simply lifting chains and jewelry at the stores’ .
1880		Colfax Chron. (Grant Parish, LA) 21 Aug. 2/3: Now when he lifts that handkerchief he drops what he has lifted into his pocket. That’s penny-weighting.
1899		S.F. Call 2 Apr. 25/5: Jewelry thieves are ‘pennyweighters’.
1903		H. Hapgood Autobiog. of a Thief 56: She was an artist at ‘penny-weighting’ and ‘hoisting’.
1904		Number 1500 Life In Sing Sing 261: I blew out and rung in with a couple of penny-weighters. A Tommy and his papa.
1909		F.H. Tillotson How I Became a Detective 89: To ‘pennyweight’ anything is to let one man ‘stall’ in a store while another one ‘lifts’ it.
1919		Eve. World (NY) 1 May 30/6: One who steals diamonds, ‘stone getter.’ Jewelry-thieves, ‘penny-weighters’.
1927		‘Jargon of the Und.’ in DN V 458: Pennyweight job, Robbing jewels.
1928		M.C. Sharpe Chicago May (1929) 137: He was only a pennyweighter, and should not have been put to work on a safe-job.
1939		Howsley Argot: Dict. of Und. Sl. 37: pennyweigher [sic] – a thief who specializes in jewels.
1951		D. Dressler Parole Chief 80: Pennyweighters [...] steal gems from jewelers in broad daylight.
1962		Ragen & Finston World’s Toughest Prison 812: pennyweight job – A jewel robbery.

2. one who steals by substituting paste gems for the real ones.

1885		Ledger (Noblesville, IN) 14 Aug. 6/2: ‘You know “Spider”, the “pennyweighter”, he is up in Mich. on the Shoe contract’.
1899		J. Flynt Tramping with Tramps 396: pennyweighters: jewel thieves.
1900		Flynt & Walton Powers That Prey 46: He an’ I are doin’ a little song an’ dance together while I fix up this pennyweight job.
1928		M.C. Sharpe Chicago May (1929) 215: Annie was an expert pennyweighter; that is, one who was familiar with the weight, size and colour of gems, and could appraise them instantly and carry the details in her mind. When it became necessary, she would buy, or have inferior or artificial duplicate-gems made, and would switch the artificial for the genuine ones. In this way she could cover a theft under the nose of the smartest dealers and usually make her getaway.
1937		(con. 1905–25) E.H. Sutherland Professional Thief (1956) 54: The pennyweighter is a professional thief who defrauds jewelers by substituting spurious articles for genuine articles while the genuine articles are being shown to him as a prospective customer. [...] This racket requires considerable knowledge of jewelry and careful planning of the job so that the spurious jewelry will not be noticeably different from the genuine articles.