Short answers, pulled from the story.
Conglomerate is a sedimentary rock composed of smaller rounded gravel fragments surrounded by finer sand and clay. Geologists call the larger fragments clasts while the surrounding fine material is the matrix. Calcium carbonate, iron oxide, silica, or hardened clay often bind these components together over time.
Scientists sort these stones based on what lies inside them to determine if they are monomictic, polymictic, or petromictic. A rock containing only one type of mineral becomes monomictic while two or more different rock types create polymictic varieties. The roundness of the gravel determines if it is a true conglomerate or an angular breccia.
Montserrat near Barcelona displays jagged vertical channels carved by erosion while Santa Maria de Montserrat Abbey uses this strong rock for construction. Crestone Conglomerate lies at the foot of the Sangre de Cristo Range in Colorado and Cliffs stretch along the east coast of Scotland from Arbroath northwards. Copper Harbor Conglomerate exists within Lake Superior's Keweenaw Peninsula and Kata Tjuta domes rise in Australia's Northern Territory.
Water and ice carry these heavy stones to new locations through mechanisms like turbidites, fluvial systems, and glacial tillites. Turbidites in deep water hold well-rounded clasts with strong alignment patterns while basal conglomerates mark shorelines during marine transgressions above ancient unconformities. Alluvial fans merge at mountain fronts to form braidplains with thick accumulations and debris flows create paraconglomerates where matrix supports floating clasts.
Heat and pressure alter standard conglomerates into metaconglomerates over geological time which changes the original texture and mineral composition significantly. The resulting rocks retain some memory of their sedimentary origins despite intense stress and often show stretched or folded clast patterns. These features help geologists reconstruct ancient tectonic events and prove that even hard stones can change shape under extreme force.