BUILDING STONES-SANDSTONE—LIMESTONE. 
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Buenai When first taken out it is readily cut into any desired form, but hardens on exposure 
to the air or after drying, but does not become too hard to work. It is necessarily much more 
expensive to work a quarry downwards, below tide, as in this case, than to split out blocks from 
a bluff above the general surface of the ground. The sandstone also lies in beds, which are of 
variable thickness, rendering it difficult to procure dimension stone of uniform size. 
Benicia .—A large quantity of sandstone of a rusted or buff color is obtained at Benicia, and 
sent down to San Francisco. It appears to be identical in its lithological characters and age 
with the partly decomposed stone of San Francisco Bay. Its principal recommendation, as a 
building material, is its cheapness and the facility with which it can be cut into blocks. It is 
very soft, as compared with the unchanged rock, and in many cases the angles of the stone can 
be crumbled off by the fingers. Its quality is far inferior to that of the undecomposed blue 
stone, it being much more friable and liable to wear away by the action of the weather. 
Fort Boss .—A light-colored gray sandstone is obtained on the coast at Fort Ross and other 
places. That from Fort Ross contains considerable carbonate of lime, and is friable. It is, 
however, more compact, and has a finer grain than the Benicia stone, and also has the appear¬ 
ance of a more durable material. It is easily worked, and takes a good polish or a very smooth 
surface on being rubbed down with fine sand. 
A peculiar building material is obtained from Mokelumne Hill, and is used to a slight extent 
in San Francisco. It is a very light and porous rock of sedimentary origin, consisting chiefly 
of fine volcanic sand and light ashes, with the fragments and dust of pumice-stone. The 
color varies from a delicate pink to light-yellow, and is very pleasing. The stone, although 
light and soft, and easily cut by a knife or saw, appears to be tough and strong. It is very 
easily worked or cut into any shape, but cannot be regarded as a valuable building material, 
except, perhaps, for temporary structures not requiring great strength. 
LIMESTONE. 
The State of California is well supplied with this material, and several localities are within 
convenient distances of San Francisco. It is found north of the city, on the shores of Tomales 
Bay, Marin county, and on the south, near Santa Cruz. It is also found near the quicksilver 
mine at New Almaden, and on the western side of the San Juan Mountain, near the road to 
Monterey. According to Rev. Walter Colton, it is found within ten miles of Monterey, and 
was used by him in the construction of the court-house. 
At all these places the rock is the white, crystalline variety, 1 found associated with granite, 
and commonly known as “primitive” or metamorphic limestone. A considerable quantity of 
lime is made, both at Tomales and Santa Cruz, and both places being upon the coast it is 
readily transported to the city. 
Tejon Pass .—Abundance of pure white limestone was found in the Tejon Pass, on both sides 
of the summit. That on the western side is at the entrance to the side ravine, leading to 
Taheechaypah prairie. On the east, it comes to the surface in a series of extended ridges, near 
the slope of the Great Basin. In some parts of these ridges the rock is snow-white and beau¬ 
tifully even in its grain, and it might appropriately be called statuary marble. 
Canada de las Uvas .—The position and peculiarities of the numerous ridges of limestone in 
this place have already been noticed in Chapter XV. The outcrops are also indicated in the 
1 A dark, reddish-brown limestone also occurs on the shores of Tomales Bay, hut the locality was not visited. A specimen 
of the rock in the collection is traversed with white veins, and is compact and fine-grained. It might be called marble.. 
