The study concerns the identification of materials and confirmation of common workshop origin and stylistic provenance of two sculptures of c. 1420–1430, preserved from among the artistic heritage of the State of Teutonic Order in Prussia: the Beautiful Madonna of Gdańsk (in Our Lady’s Basilica in Gdańsk) and – partly destroyed – figure of Madonna from St Ann’s Chapel in Frombork (presently in the collection of the Nicolaus Copernicus Museum). Those statues, alienated from the background of the art of the region both due to their stone fabric and to their artistic form and monumental scale, had been sculpted in the same stone, most probably acquired in one of the quarries in the Scheldt river basin in the same workshop of a decidedly Western artistic formation. Even though the identification of material does not definitely decide on their artistic origin, it allows to seek the wellspring of their style in Franco-Netherland art much more confidently than before. It can not be finally decided whether the sculptures were made in Pomerania, in the workshop of a Netherland artist, for whom the stone was brought down from the region of Hainaut– Artois / French Flanders or whether they were imported from Southern Netherlands. The latter possibility however – combining the origin of raw material and the origin of artistic form – seems much more probable. The text presents in detail the methodology of testing the samples acquired from both sculptures and the derived conclusions that prove great potential of petrographic analyses in art history. It also extends the comparative characteristics of both artefacts against the background of European sculpture of the 1st half of 15th cent. The study aims – on one hand – for establishing their provenance in confrontation with the results of the analysis of the stone (especially important both for regional studies and for world studies on the Beautiful Style); on the other and – for introducing into the wider discussion on the geography of stone sources and the fabric of ...