The rock is sedimentary and It 90% red , 3% white and the remaining 7% light grey. Characteristic is the reddish color indicating strong oxidation of the sediment. This rock is a conglomerate because it is composed 90% by coasts that have dimensions ranging from 1 mm to 5 mm and a small part of the remaining 10% from clasts with a dimension of 1 cm The conglomerates are partly made up of lithic fragments of milky and pink quartz, volcanic and partly metamorphic rocks. These rocks originated from deposits of alluvial fan and alluvial plain. The composition of the Verrucano indicates an origin of the deposits due to erosion of part of metamorphic rocks, in part of the Permian volcanic and terrigenous covers. These are red siliciclastic deposits, characterized by alternations of sandstones and conglomerates sedimented in the fluvial environment. conglomerates can have very variable granulometry, alternating with medium-coarsegrained sandstones, with quartz-feldspar composition, abundant matrix and siliceous-clayey cement.
The Verrucano Lombardo is a geological unit of the late Permian age. There are frequent outcrops along the entire pre-Alpine belt from Valsàssina to Val Camonica and from Val Camonica to Valli Giudicarie. Also present in Val Seriana and Val Brembana, thanks to the presence of the Serio and Brembo rivers, the sediments have also reached the Bergamo area.
The name verrucano derives from Monte Verruca, in the area of Monte Pisano in Tuscany, where there is a similar conglomerate, but of the Triassic age.
It is a tough, abrasive stone, difficult to carve. It is used to build: paving stones, stone walls, millstones, fountains, drinking troughs, mortars for piling, milestones. Due to its color and wear resistance, it is often used to make tiles for external cladding or for paving squares, perhaps alternating with carbonate pebbles. For example in Bergamo it was used for the cobblestones in Piazza Vittorio Veneto. In Valle Camonica, many artifacts have been obtained not only from small local quarries, but also from erratic boulders, transported and then deposited by glaciers. One of these boulders nicknamed Balunton is about 3-4 meters large.
The church dedicated to St. John the Baptist. The church, with a classic east orientation, has a linear gabled façade. The side part is made of local Verrucano stone and inserted in the ancient private houses. The façade divided into two orders is divided into three parts by four pilasters with high concrete plinth and ending with simple capitals that support the frame of the string course. The lower order presents the entrance with a portal of the sixteenth century with pilasters in Sarnico stone and the IHS trigram of San Bernardino da Siena in the entablature. The portal ends with the broken tympanum. The interior has a single nave with a barrel vault and is divided into four spans by pilasters with a high plinth in gray Ardesio marble. The pilasters end with the cornice which has openings in the upper part designed to illuminate the classroom. The presbytery, preceded by the triumphal arch, has a rectangular plan, always with a barrel vaulted roof. This is illuminated by skylights. The main altar is in carved and gilded carved wood, while the apse ends with the wooden choir and the carved wooden anchor with the canvas depicting the Capitation of John the Baptist. The nave, which is accessed by a wooden compass, is completely frescoed. Above the compass there is the organ inserted in the choir in inlaid wood, with the busts of St. John XXIII and John Paul II. In the vault of the first span there are two medallions with stucco frames depicting the Birth of John the Baptist and San Camillo de Lellis and San Rocco. The baptismal font is placed in the second span with a basin in Ardesio marble with a temple covering in carved walnut. The third bay also has a side exit with a compass where the image of Don Francesco Brignoli is engraved in the carving. The vault depicts the Baptism of Jesus in the waters of the Jordan, with stucco medallions depicting Saints Francis de Sales, Peter and Paul and Saint Charles Borromeo. The fourth span has painted the four evangelists on the vault, while the altar on the right is dedicated to the Madonna della Consolazione with the seventeenth-century canvas depicting the Madonna of the belt with saints, in front of that of the Madonna del Rosario with the small panels depicting the mysteries of the rosary.
The square is located in the heart of Bergamo, between via Roma and via Sentierone. It forms, with the contiguous squares Matteotti, Dante and della Libertà, the center of lower Bergamo; the modern system of squares, built in the area of the demolished S. Alessandro fair, was built at the beginning of the twentieth century on a project by Marcello Piacentini. it consists of bowls of Lombard wart along with carbonate pebbles.
