File:"Columbia Pink Granite" (porphyritic granite, Conway Granite, Jurassic; east of Tinkerville, New Hampshire, USA) (14618798910).jpg

"Columbia Pink Granite" - porphyritic granite from the Jurassic of New Hampshire, USA.

"Granite" in the decorative stone trade is any relatively hard rock that will take a fine polish, regardless of mineralogy or chemistry or geologic origin.

"Granites" turn out to be felsic to mafic intrusive igneous rocks (granite, granodiorite, porphyritic granite, rapakivi granite, orbicular granite, pegmatitic granite, graphic granite, anorthosite, monzonite, gabbro, norite, gabbronorite, dolerite, diabase, charnockite, etc.) and high-grade to very high-grade metamorphic rocks (metanorthosite, gneiss, metaconglomerate, amphibolite, quartzite, granulite, migmatite).

True granites (= monzogranites & syenogranites & porphyritic varieties) make up most of the commercial granite trade. Countless varieties are quarried around the world.

Columbia Pink Granite is 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. In the 2000s, 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.