Task: Question Generation
Input (English): Passage: The chief building material of the church is buff sandstone, which came from the Goodrich Quarry (also called the Greystone Quarry) in the Almaden area of San Jose, was delivered by train and rough-cut in the university Quad.  Gregg credits the high quality of the stonework to church and university builder John D. McGilvray.  The church is roofed with terracotta tiles of the Italian imbrex and tegula form. The nave, chancel, and transepts appear to project from the square central structure, roofed with tiles and a small skylight above its center.  Memorial Church originally had a central bell tower with an 80-foot tall, twelve-sided spire, but this was lost as a result of the 1906 earthquake.The church's facade is surmounted by a simple Celtic cross, a motif that appears several times throughout the building.  The cross was added after the 1906 earthquake; its central shaft was destroyed in the Loma Prieta earthquake and replaced.  There are three arched entrances below the exterior mosaic; the central one is slightly larger than the others.  The surrounding stonework is intricately carved with stylized flora, twisted-cable moldings, and bosses of sculpted cherubim, a motif which occurs in different media throughout the church. In the spandrels are mosaic depictions of the biblical concepts of love, faith, hope and charity intertwined in a vine representing the "tree of life".In the upper zone of the facade, surrounded by more elaborate stonework and "lacy carving", is a large central window, with groups of three smaller windows on each side.  The original central window was a quatrefoil-shaped rose window, but after the 1906 earthquake, it was replaced by a "classical round-head window that more grandly restates the smaller flanking, articulated openings" and that corresponded with the mission-style architecture of the Quad.  Beneath the windows are inlaid panels of colored marble.
Output (English): What church's chief building material was buff sandstone?