The 20-year-old trained with the Gills on Thursday and goes straight into their squad for Saturday's home clash against Dagenham.
Richardson is yet to make a first-team appearance for the Magpies but spent time on loan at npower League One side Leyton Orient last season, making four appearances and scoring once.
His arrival comes after that of Fulham winger Ryan Williams on a 28-day deal.
- Sports & Recreation
- Leyton Orient