The marble of Siena in medieval art and architecture

The use of crystalline limestones yellow, gray and white of the quarries of Montagnola is mainly linked to the construction of religious buildings.
So we find the marble of Siena in the parishes of Montagnola (XI century) and, from the fourteenth century, in the city of Siena in the first place in the Cathedral of Siena, but also in other monumental buildings, such as the lining of the Lodges of Pope and the Lodges of Merchandise, as well as in works of art as the Fonte Gaia, fifteenth-century masterpiece by Jacopo della Quercia. In this period, the Marble Montagnola is also used in important architectural works of central Italy, such as Florence Cathedral and the Cathedral of Orvieto.
The white varieties were used mainly as a building stone in square blocks, while the yellow varieties were used to make ornaments in the interior, such as the 1,300 square meters of colorful mosaics of the floor of the Duomo of Siena.
A collection of "Specimens dei Marmi used dell'Opera del Duomo di Siena" and its quarries of origin is on display at the Natural History Museum of Siena, valuable source of information for the restoration and maintenance of the monument. In six to seven hundred are witnessing a certain decadence of the white varieties, due to the start of the import of Apuan marble characterized by a stronger structure, and therefore more resistant to weathering, and at the same time the success of the yellow varieties, so that in this period occurs the development of all areas of cultivation of Giallo di Siena. In fact, the Grand Dukes of Tuscany promote a genuine policy of self-sufficiency of the stones, and the Giallo di Siena is widely used by the Florentine manufacture Opificio delle Pietre Dure for making architectural decorations, pieces of furniture and precious objects.