A Michigan jeweler was sentenced to seven months in jail and five years of probation by Van Buren County Circuit Court after he reportedly admitted switching a customer’s diamonds with moissanite, according to local press reports.

Randy Block, 43, of Paw Paw, Mich., pled guilty to one count of larceny by conversion. He has also been ordered to pay restitution to his victims.

Police launched an investigation in December 2003 after a woman became suspicious about a diamond ring that Block returned to her.