KINDS OF ROCKS. 427 
bles. f. Ferruginous ; containing iron oxide and having its red color. 
g. Concretionary ; made up of concretions. h. Laminated ; made up 
of thin layers or lamins, or breaking into thin slabs, a characteristic 
most prominent in argillaceous sandstones. i Hable ; crumbling in 
the fingers. j. Mossiiferous ; containing fossils. 
The paving stone extensively used in New York and the neighbor- 
ing States is a laminated sandstone, of the upper part of the Hamilton 
group in geology, quarried just south of Kingston, and at many other 
places on the west side of the Hudson River. The rock is remarkable 
for its very even lamination. In Western New York and in Ohio, the 
Devonian sandstones, above the Hamilton group, together with the 
Waverly group, afford a similar flag-stone. ‘The ‘‘ brown-stone” used 
much in New York and elsewhere for buildings, is a dark-red sand- 
stone from the Triassic formation, and is quarried at Portland, Conn., 
on the Connecticut River, opposite Middletown. A lighter-colored 
“« brown-stone ” or ‘‘ free-stonc,” of the same age, also much used for 
buildings, comes from Newark, Belleville, Little Falls, and other points 
in Central New Jersey. The handsome sandstone of light olive-green 
‘tint, much employed in architecture, is from the Lower Carboniferous 
group in New Brunswick. The soft white sandstone, in much esteem 
among architects because so easily cut and carved, comes from Ohio 
quarries, in beds of the Carboniferous ; it is mostly from a bed about 
sixty feet thick, called the ‘‘ Berea grit,” and is obtained at Berea and 
Independence in Cuyahoga County, and Amherst in Lorain County, and 
elsewhere. 
Pyrite is often present in sandstones used for building, and has de- 
faced, and is destroying, many a beautiful structure by its oxidation, 
and the consequent decay of the rock. 
Sandstones absorb moisture most easily in the direction of the bed- 
ding or grain, if there is any distinct bedding ; and hence the blocks, 
when used fora building or wall, should be placed with the bedding 
horizontal. It is, further, the position in which the stone will stand 
the greatest pressure. 
Grindstones are made from an even-grained, rather friable sand- 
stone, and are of different degrees of fineness, according to the work 
to be done by them. 
Hard siliceous sandstones and conglomerates, occurring in regions of 
metamorphic rocks, are called ‘‘ granular quartz,” and quurtzyte (p.435). 
4. Sand-rock.—A rock made of sand, especially when not 
of siliceous material. A calcareous sand-rock is made of cal- 
careous sand ; it may be pulverized corals or shells, such as 
forms and constitutes the beaches on shores off which living 
corals and shells are abundant. - 
The beach sands become cemented below high-water mark into a 
calcareous sand-rock, which consists of layers having the pitch of the 
surface of the beach. They are often coarse, calcareous conglomerates. 
5. Shale.—A soft, fragile, argillaceous rock, having an 
uneven slaty structure. Shales are of gray, brown, black, 
dull-greenish, purplish, reddish and other shades. 
