Columbia Pink Granite - a scarce decorative stone variety from New Hampshire. It comes from a now-inactive quarry near Meriden Hill, 2 miles east of Tinkerville in western Coos County, northern New Hampshire . It's an attractive porphyritic granite with quartz (gray), K-feldspar (pink), sodic plagioclase feldspar (whitish), and biotite mica (black). This rock comes from the Jurassic-aged Conway Granite (White Mountain Plutonic Series).
Columbia Pink Granite is no longer quarried. Recently, however, material was specially obtained & used to replace the Pentagon's entrance steps that were destroyed by the 9/11/2001 terrorist attacks in Washington D.C. The original steps were composed of Swenson Pink Granite from Maine, which is no longer available. Columbia Pink Granite was considered to be a close match.