Thieves assaulted and robbed a driving instructor as she gave a lesson in Crumpsall last week.
The 55-year-old woman was in her car, at about 6.20pm on July 19, with a 44-year-old client on Catherine Road.
Both were sitting in the black Vauxhall Corsa, which was stationary, when two men approached, opened the doors and demanded their possessions.
One offender grabbed an earring and tore it from the victim’s ear, causing it to bleed, snatched her necklace from her and used pliers to cut through a bangle she was wearing on her wrist.
He then grabbed her handbag, which was secured by a strap around her neck and snatched it from her, causing the strap to break.
During the struggle to get her handbag he hit her in the face with his pliers, causing minor facial injuries.
Both men then ran off towards Middleton Road.
Nothing was taken from the woman having a driving lesson and she was uninjured.
The first offender was white, in his late teens or early 20s, about 5ft 9in tall, of thin build with a skinny face and wearing a cream coloured baseball cap.
His accomplice is described as white, between 20 and 25 years old, of slim build with short cropped hair and wearing a dark blue hooded top.
Detective Constable Pete Murphy, said: "Both women were focused on the driving lesson and have been left understandably shocked and upset by what happened.
"One was subjected to a violent and frightening assault and robbery and I believe this was nothing more than an opportunistic and desperate act.
"We have some images of the jewellery and are doing all we can to identify the offenders and recover the property but if you saw what happened or have been offered the items please get in touch.
"I am particularly keen to hear from anyone who offers cash for gold, be it independently or in a local store, and who may have been approached by someone trying to sell these items."
The items stolen include:
A 22 carat gold earring
A diamond cut ‘D’ shaped clip with an etched pattern.
A 22 carat gold bangle style bracelet. Half of it is made up of a three wire configuration with the other being a honeycomb design.
A 22 carat gold necklace, diamond cut ball and chain design.
Black leather shoulder handbag.
Anyone with information is asked to contact the CID office at Central Park Police Station on 0161 856 3240, or Crimestoppers, anonymously, on 0800 555 111.