The Commercial Granites of North Carolina
17
RALEIGH GRANITE AREA
Many years ago rather extensive quarrying operations were carried on in the immediate vicinity of
Raleigh for the production of dimension and crushed stone for local use. The State Capitol building and
many of the older churches and homes of the city are constructed of a granite-gneiss, locally called “Wake-
stone.” This type stone is a uniformly fine- to medium-grained rock of approximate granitic composition,
usually displaying a marked parallelism of all mineral constituents. Colors range from light gray to grayish
tan, which upon exposure weathers to a mottled tan. Large blocks of the stone almost inevitably show pene¬
tration by aplite or fine-grained pegmatitic material. Wakestone was formerly obtained from three large
quarries, two of which were within the corporate limits of Raleigh.
The City Quarries: Two large openings were worked in the vicinity of the National Cemetery, about
1.5 miles east of the Capitol building, beginning about 1833 and continuing intermittently until after 1903.
Stone from these quarries was used in the construction of the State Capitol buiding. According to Watson
and Laney, jointing in the rocks of this area is at fairly close intervals and strikes approximately E. Within
the quarries, many areas of mineral segregation are present and usually occur as vein-like bodies, conforming
to an approximate N. strike. The vein and dike materials consist of pegmatite, aplite, and quartz, and all
show evidence of minor displacement since intrusion.
Petrographically, Watson and Laney describe Wakestone, as follows:
“. . . in order of their abundance . . . feldspar, quartz and biotite. The feldspathic constituent
consists of the potash varieties, orthoclase and microcline, with a nearly equal proportion of striated
acid plagioclase. Microcline nearly equals orthoclase in amount. . '. . micropoikilitic structure is
fairly wrell developed. . . . Biotite is distributed through the sections. . . . Zircon and apatite . . .
complete the list of minerals.”
Based on the definitions given earlier in this report, Wakestone from these quarries falls into the class quartz-
monzonite gneiss.
The Sutton Quarry : A recent revival of interest in Wakestone for building purposes has resulted in the
opening of a small quarry in north Raleigh, near Lassiter Mill. According to Mr. Sutton, the owner, dimen¬
sion stone of small size is used locally to a rather large extent, especially in the building or enlargement of
schools and churches and as a trim stone. Stone from the small quarry is decidedly gneissic and corresponds
in composition with the stone from the old City Quarries. Colors in the deposit are generally a gray-tan to
mottled tan and present a pleasing appearance. The joint systems are well developed, but vein and dike
materials are almost entirely absent.
Other Quarries: Other openings in granite-gneiss were made in Wake County in the vicinity of the State
Penitentiary and 2 miles northwest of Raleigh, both furnishing dimension stone for local use. In general,
the rock type corresponds with that of the City Quarries, though locally it may become more or less gneissic.
The Crabtree Quarry: This small bench-type quarry is located about 3.5 miles northwest of the Raleigh
city limits, 0.75 of a mile south of U. S. Highway 70, and adjacent to Crabtree Creek. Although now aban¬
doned, the quarry has in recent years produced crushed stone for county road repairs and remains in excellent
condition for further use. The rock is a light gray granite-gneiss of medium- to large-grained texture, in
which dark silicates are almost entirely absent. Shear is prominent, cutting the deposit into blocks of small,
irregular dimension. A thin section of the rock shows the following minerals and their percentages:
Quartz . _ 32%
Orthoclase — _ .35%
Plagioclase _ 10%
Biotite _ 8%
Others (zircon, apatite, tourmaline, magnetite,
calcite, muscovite, sericite) _ 15%
Accordingly, the rock falls into the class granite-gneiss. Significant features observed in the thin section
were: (1) numerous tangential grain contacts, which constitute the most prominent microscopic charac¬
teristic of the rock, (2) the presence of considerable sericite, formed by the alteration of the feldspar con¬
stituents, (3) the abundance of accessory minerals, and (4) fine mosaics of quartz filling the interstitial
