Question: What is Grand Central terminal made from?
About the article "Grand Central Terminal", section "Grand Central Terminal".

Candidate passages:
Grand Central Station is widely used informally to refer to Grand Central Terminal, a major railroad terminal in New York City, or as a figure of speech to mean any very busy place.
It may also refer to: Grand Central – 42nd Street (New York City Subway), the New York City Subway station complex adjacent and attached to Grand Central Terminal.
Grand Central (IRT elevated station), a former station active 1878–1923 Grand Central Station (Chicago), a former train station in Chicago Grand Central Station (radio), a radio series running from 1937 to 1954 United States Postal Service office near Grand Central Terminal  
Mamaroneck Metro-North Railroad station serves Mamaroneck, New York, via the New Haven Line.
Mamaroneck is from Grand Central Terminal and the average travel time from Grand Central is 43 minutes. 
Many exterior shots were made at the Grand Central Air Terminal, Glendale, California. 
Between 1903 and 1913, the entire building was torn down in phases and replaced by the current Grand Central Terminal, which was designed by the architectural firms of Reed and Stem and Warren and Wetmore, who entered an agreement to act as the associated architects of Grand Central Terminal in February 1904.
Reed & Stem were responsible for the overall design of the station, Warren and Wetmore added architectural details and the Beaux-Arts style.
Charles Reed was appointed the chief executive for the collaboration between the two firms, and promptly appointed Alfred T. Fellheimer as head of the combined design team.
This work was accompanied by the "electrification" of the three railroads using the station and the burial of the approach in the Park Avenue tunnel.
The result of this was the creation of several blocks worth of prime real estate in Manhattan, which were then sold for a large sum of money.
In addition, the terminal itself contains support structures for a possible future tower to be built above it.
The new terminal opened on February 2, 1913.
The terminal is made primarily from granite.
In fact, so much granite is used, the building emits relatively high levels of radiation on a regular basis.
From 1922 to 1958, Grand Central Terminal was the home of the Grand Central Art Galleries, which were established by John Singer Sargent, Edmund Greacen, Walter Leighton Clark, and others.
The founders had sought a location in Manhattan that was central and easily accessible, and through the support of Alfred Holland Smith, president of the New York Central Railroad, the top of the terminal was made available.
A 10-year lease was signed, and the galleries, together with the railroad company, invested more than $100,000 in preparing the space.
The architect was William Adams Delano, best known for designing Yale Divinity School's Sterling Quadrangle.
At their opening, the galleries extended over most of the terminal's sixth floor, , and offered eight main exhibition rooms, a foyer gallery, and a reception area.
A total of 20 display rooms were planned for what was intended as "...the largest sales gallery of art in the world."
The official opening was March 22, 1923, and featured paintings by Sargent, Charles W. Hawthorne, Cecilia Beaux, Wayman Adams, and Ernest Ipsen.
Sculptors included Daniel Chester French, Herbert Adams, Robert Aitken, Gutzon Borglum, and Frederic MacMonnies.
The event attracted 5,000 people and received a glowing review from "The New York Times".
A year after they opened, the galleries established the Grand Central School of Art, which occupied on the seventh floor of the east wing of the terminal.
The school was directed by Sargent and Daniel Chester French.
Its first year teachers included painters Jonas Lie and Nicolai Fechin, sculptor Chester Beach, illustrator Dean Cornwell, costume designer Helen Dryden, and muralist Ezra Winter.
The Grand Central Art Galleries remained in the terminal until 1958, when they moved to the Biltmore Hotel.
When the Biltmore was demolished in 1981 they relocated to 24 West 57th Street.
They ceased operations in 1994.