Because of the stringent laws prohibiting silversmiths from practising their craft in Brazil which were in effect for much of the 18th century, many pieces made by clandestine craftsmen working in Bahia and in Rio de Janeiro are struck with marks in imitation of official Portuguese hallmarks. Manuel Goncalves Vidal lists a number of Oporto and Lisbon marks used in Brazil at this time in Marcas de Contrastes e Ourives Portugueses, vol. I, nos. 2569-2572. For a pair of Brazilian lanterns struck with Oporto marks, circa 1770, see Christie's, New York, October 30, 1990, lot 71.