(ABC News) -- Al Capone's diamond-studded, platinum pocket watch and other artifacts that belonged to some of America's most notorious gangsters are being auctioned Saturday.
Capone's watch, as well as a musical composition he handwrote behind bars in Alcatraz, are among the items up for bid in the "Gangsters, Outlaws and Lawmen" auction in Massachusetts on Saturday by RR Auction, an auction house headquartered in Boston.
Capone, who was born to Italian immigrants in New York City, headed a Chicago-based crime empire during the Prohibition era that raked in millions of dollars through bootlegging, gambling, racketeering and other illicit activities. He was dubbed Scarface by the press after his face was slashed during a fight, a nickname he apparently disliked.
"Unlike his more maligned moniker of ‘Scarface,’ Capone preferred that those closest to him call him by ‘Snorky,’ a slang term which meant ‘sharp’ or ‘well-dressed,'" according to a description accompanying Capone's watch on RR Auction's website.
According to the auction house, the rounded triangular pocket watch was personally owned and used by Capone. The timepiece is on its original chain made of 14-karat white gold. The exterior of the case features 23 diamonds shaped to form Capone's initials, "AC," which are encircled by 26 additional diamonds. Another 72 diamonds circle the watch's platinum face and gold-tone impressed numerals.
Online bids for Capone's watch had surpassed $17,000 prior to the live auction Saturday afternoon. Experts estimate the item will sell for more than $25,000, according to RR Auction.
A musical piece entitled "Humoresque," written in pencil by Capone when he was incarcerated in Alcatraz in the 1930s, is also up for grabs. The musical manuscript shows Capone's softer side, containing the lines: "You thrill and fill this heart of mine, with gladness like a soothing symphony, over the air, you gently float, and in my soul, you strike a note."
Experts estimate the sheet will sell for over $20,000, according to RR Auction.
Also up for auction are a letter written by gangster boss John Gotti, two life-size death masks of gangster John Dillinger, a brick from the scene of the 1929 St. Valentine’s Day Massacre, and jewelry that belonged to infamous crime duo Bonnie and Clyde.
Online bidding for the items ended Friday. A live auction was scheduled for 1 p.m. ET on Saturday at the Royal Sonesta Hotel in Cambridge, Massachusetts.