The couple were attacked in their home on South Park Drive, Ilford
In the early hours of Monday morning, the couple, in their late 50s, awoke to find two men in their room in their Ilford home in Essex.
One of the attackers proceeded to hold the woman down by putting a foot on her chest to restrain her.
He then used a pair of pliers to remove the necklace, while ordering her to give him more jewellery.
This was a terrifying ordeal for the victims and it has left them extremely distressed
Detective Constable Sophie Mostyn of Redbridge CID
In the meantime, the second assailant stood over her husband and pointed a knife at his neck during the robbery in South Park Drive.
After the attack, the pair became aware of more people in the house, and escaped through the back garden.
The police were called by the couple's 20-year-old granddaughter shortly before 3am, who was also in the property, but they are yet to make an arrest.
The burglar cut the necklace from around the woman's neck
Scotland Yard issued a description of the attackers, who wore dark clothing. The pair were a white and a black male in their mid-to-late 20s.
However, the police are currently appealing for any information on the subject.
The burglars broke into the couple's home in the early hours of Monday morning
Detective Constable Sophie Mostyn of Redbridge CID said:
“This was a terrifying ordeal for the victims and it has left them extremely distressed.
“We are determined to catch those responsible and put them before the courts.
Scotland Yard issued a description of the burglars, but are appealing for more information
“We'd appeal for anyone with any information to contact us as a matter of priority.”
Anyone with information should call police on 101 or Crimestoppers anonymously on 0800 555 111.