[Illustration: The Corcoran Gallery is built mostly of marble.]
The Corcoran Gallery is marble with a granite base. It was built in 1879
and enlarged in 1927. Ornate carvings around the roof, doors, and
windows have blackened crusts of gypsum, as do parts of the marble
pedestals supporting the bronze lions at the front door. The marble
bases also have inclusions that stand out above the surrounding calcite,
which has been dissolved away.
[Illustration: Marble bases for bronze lions outside the entrance to
the Corcoran Gallery have feldspar inclusions that stand in relief
compared to the roughened surrounding calcite.]
Continuing north along 17th Street towards Pennsylvania Avenue, you
will see several modern granite office buildings and the Executive
Office building (formerly the State-War and Navy building), which was
built from granite and completed in 1888. These granite buildings show
little deterioration. Turn right onto Pennsylvania Avenue and proceed
to the Renwick Galley on the northeast corner of the intersection of
17th Streets and Pennsylvania Avenue.