A TEENAGER who stole jewellery worth £2,500 from his girlfriends grandmother has been jailed for eight months. Luke Grantham, of Stonehill, St Neots, took the rings during regular visits to Julia Arnolds house, and sold them on for just £150 to fund his drug habit, Peterborough Crown Court heard on Wednesday. The jewellery included two rings of particular sentimental value to Mrs Arnold, who was assisted by Grantham in a search for the items. He suggested that she had mislaid the rings, a deceit she called unforgiveable. The 18-year-old, who was already on a conditional discharge for an offence of theft in September 2010, also took a £50 Dixons voucher, which he tried to sell on to his own family. The court heard that Mrs Arnold, who is in her mid-50s and suffers with a spinal condition, first noticed the rings were missing in November of last year, and suspected that Grantham may have been involved. She called Granthams mother, who confirmed that she had been offered the voucher. Grantham admitted to his girlfriend he had stolen the rings and sold them to a jeweller in the St Neots area, but the rings had already been melted down. The matter was reported to the police, and Grantham made full admissions. He pleaded guilty to the theft at Huntingdon Magistrates Court on January 5. In a statement given to police, Mrs Arnold said she had been left hurt but also very angry. Im a straight and honest person. He has crushed me with how he has behaved. The court heard that Mrs Arnold considered two of the rings invaluable, as they had been given to her by her mother. She said: I will never see them again. Thank God I still have my memories because that is all I have now. John Kirkpatrick, mitigating, said that Grantham was deeply remorseful for his actions. He accepts it was a gross breach of trust and he is genuinely ashamed. He said that at the time of the thefts Grantham had been using cannabis and ketamine regularly, but that he was now clean after having spent three weeks in custody. He explained Grantham had endured a troubled and violent upbringing, but that he now wanted to turn his life around. His time in custody is tearing him apart. He said he has never felt lower in his life, said Mr Kirkpatrick. He was unlucky enough to have a childhood, way before 12 and right up to 16, that none us would like to endure. Judge Sean Enright said Granthams crimes were serious that custody was the only option, and sentenced him to eight months for the theft and one month, to run concurrently, for the breach.