Two Chicago crooks stole the Marlborough Diamond 43 years ago. They did time, the gem remains at large.

Arthur Rachel and Joseph Scalise had to be full of themselves when a British Airways jet reached the gate at O’Hare Airport’s international terminal on Sept. 11, 1980.

A few hours earlier, they had robbed a London jeweler of the 45-carat Marlborough Diamond. The centerpiece of Laurence Graff’s display window, the stone was famous before the Chicago hoodlums committed what seemed a perfect crime.

“They picked out the very special pieces from the window,” Graff said “It was all over in less than a minute.”

Scalise and Rachel, both in their early 40s, wore disguises to pull off their heist and knew that if London’s cops ran witnesses’ descriptions of the robbers through albums of mug shots, they couldn’t have found a match.

But Chicago cops knew Scalise and Rachel only too well.

“Their rap sheets read like a Who’s Who in burglary and robbery in the United States,” said Gary Shapiro, a federal prosecutor in Chicago who was known for going after mobsters.

During one stint behind bars, Rachel got a high score on an IQ test. In underworld circles his moniker was “the Genius.” Scalise’s moniker was “the Monk,” because he allegedly once wanted to be a priest.

FBI agents arrested both men as they went through customs at O’Hare. Scotland Yard had pieced together clues Scalise and Rachel left behind.

Judged by the bumbling robbery of the jewelry store, Rachel was no genius.

Arriving in London several days earlier, he and Scalise had carefully surveyed Graff’s. Because it dealt in big-bucks jewelry, a customer couldn’t casually walk in. Ringing the doorbell alerted employees to give the prospective customer the once-over: Did they look like someone who could afford the six-figure price tags?

Accordingly, Rachel decided he and Scalise would be decked out like Saudi princes: flowing robes or finely tailored suits, a headscarf or fedora, and facial hair to obscure their features.

Despite the careful planning, the caper began with a costume failure. A witness “was walking on the street with his girlfriend when he saw Rachel’s false beard detach from his chin,” The Associated Press reported.

The witness, a Graff’s accountant on his lunch break, later told Scotland Yard he immediately thought of Shakespeare’s words: “Something is rotten in the state of Denmark.”

Scalise rushed into the store waving a revolver. Holding what appeared to be a grenade, Rachel followed. Two customers and five employees hit the floor. Saying not a word, the Chicago gangsters grabbed the Marlborough Diamond plus other assorted gems and were gone.

Outside the store, the witness followed them to a Fiat Mirafiori and gave the police its license plate number.

It was that of a Hertz car rented at Heathrow. Incredibly, it had been booked under Rachel’s name, he had also used his own credit card.

While they were in the air, Jack O’Rourke’s phone rang in the Chicago office of the FBI. His purview was the Outfit’s street crews.

“I can still hear that British detective’s voice,” O’Rourke told Chicago magazine for a May 2012 article. “He asked, ‘Would you know a chap named Skull-lee-cee?’ I answered, ‘Do I know him? He’s practically my hobby.”

The British detective passed on Scalise and Rachel’s flight number and arrival time. They were charged with conspiracy to transport stolen property.

Yet the Marlborough Diamond wasn’t on them or in their luggage when they were arrested.

Near the London airport, Scalise and Rachel had abandoned the Fiat and taken a cab to Heathrow. They asked the driver to mail a small package. Scotland Yard found the mail clerk who handled it and brought him to a hypnotist.

Even in a trance, all the clerk could recall was that the box bore a New York address. As Scalise’s sister lived in New York, some sleuths, professional and amateur, assumed that’s where the package went, and that the Marlborough Diamond was in it.

After their arrest, Scalise and Rachel spent almost three years in the Metropolitan Correction Center in Chicago while their lawyers fought the British government’s effort to have them extradited.

Rachel’s attorney argued that a psychiatrist found him mentally incompetent to stand trial.

“At an interview with the psychiatrist, Rachel claimed he was being followed and spied on by federal agents and claimed he ran over a gymnastic (smaller than average man) who was hiding under his car to spy on him,” the Tribune reported.

A federal prosecutor countered that Rachel was faking it, and in 1983 the Justice Department handed him and Scalise over to detectives from Scotland Yard.

In London, the authorities leaned on Rachel and Scalise to tell them where the Marlborough Diamond was, promising a reduced sentence and other inducements.

The Chicagoans, hardly newcomers to the ways of cops, knew the drill.

Rachel was a resident of the Illinois Training School for Boys in Kane County in 1954 when his name appeared in a brief news item in the Tribune after he escaped “from a cornfield near the school where he had been assigned to pick corn” in a car he stole from an employee. Ten years later, Rachel was arrested as part of a counterfeiting ring accused of making fake U.S. Savings Bonds and traveler’s checks. Scalise ran with Harry Aleman, the Chicago Mob’s enforcer, and also had a criminal record.

When asked about the Marlborough Diamond at Scotland Yard, Rachel and Scalise clammed up. Their stance was that they never heard of the celebrated gem, which was named for its former owner.

It had arrived at Graff’s upon the 1977 death of Gladys Deacon, who by birth was a member of a wealthy American family, and eventually the wife of the Duke of Marlborough, Winston Churchill’s cousin.

“I never saw a girl with such beauty, such magnificent intelligence, such goodness and charm,” French novelist Marcel Proust once wrote of her.

At some point, fearing her looks were fading, the Duchess of Marlborough had plastic surgery. It was botched, her face was disfigured. She died a recluse.

When they wouldn’t say where her diamond was, Rachel and Scalise were given 15-year prison sentences in England. O’Rourke came over hoping to visit them. Give us something, and the U.S. government will get you home, he planned to say.

Scalise sent O’Rourke a letter quoting the philosopher Nietzsche: “You have your way. I have my way. As for the right way, the correct way, and the only way, it does not exist.” The Monk was a bookish sort.

Released after 13 years, Scalise and Rachel returned to Chicago and resumed their criminal careers. They weren’t spring chickens as U.S. District Judge Harry Leinenweber noted in 2012, when giving the 74-year-old Rachel a sentence of eight years and five months for plotting to rob an armored truck and an Outfit boss’s home.

“What possessed you to get involved in this caper after you (already) spent half your life in prison?” the judge asked.

“It’s the way we are,” Rachel told the judge. “We were bored. We got nothing better to do.”

Rachel had been arrested two years earlier as he sat in the back of a van outside the fortresslike home of the late mob boss Angelo “the Hook” LaPietra. The cops had bugged the van and listened in as Rachel and his colleagues, including Scalise, cased banks and armored cars.

Transcripts of the recordings read like the duo’s philosophy of crime. They made a virtue of age. “They’re looking for some young guy,” Scalise was recorded as saying about investigators. “But there’s no coppers that know us today.”

Rachel at one point wanted toothpaste to fill the holes the gang had surreptitiously drilled in LaPietra’s house. It was a trick, he said, he learned from IRA prisoners he and Scalise had befriended while imprisoned overseas.

The Marlborough Diamond’s fate still remains unknown. At the duo’s court appearances, reporters inevitably asked if the gem could ever be located.

“If Lloyds (of London) wanted to pay enough money,” the Monk said, referring to the famed insurer, “maybe they could.”

Have an idea for Vintage Chicago Tribune? Share it with Ron Grossman and Marianne Mather at rgrossman@chicagotribune.com and mmather@chicagotribune.com .