Police said the women, aged 18 and 21, arrived at Birks around 2 p.m. on Saturday.
According to Const. Franco Di Genova of Laval police, when one woman asked to try on a watch that cost $10,735, the other woman allegedly pepper-sprayed the store security guard.
Di Genova said both women ran for it, fleeing the mall and running to the nearby Sheraton Hotel.
There, they allegedly pepper-sprayed a hotel employee.
Di Genova said when police tried to arrest them a few minutes later, one of the officers was pepper-sprayed before they were successfully apprehended.
The women, from the Toronto area and Halifax, have been charged with a litany of offences, including theft, armed assault, conspiracy to commit armed robbery and possession of a prohibited weapon.
Their bail hearing is Tuesday in Laval.
Di Genova said the prosecution would contest their release.