Ball: Building and Ornamental Slones of India. 
119 
PART 3 .] 
The rocks of the Sivalik and Nahan groups which represent the upper and middle 
tertiary period of Europe are generally too unconsolidated to form durable building stones. 
These rocks, as is well known, form the outer ranges of the Himalayas at various places 
from west to east- 
Mr. Medlicott remarks : “ Those stations, as Dagshai, Kasaoli, Subathu, Dhurmsala, 
which are built on the eocene groups of the Suh-Himalayan series, have an unfailing supply 
of good building material in the massive sandstone rocks. Among the older rocks there is 
no stone fit for anything but that for which rough rubble may he used. There are several 
examples of native architecture along the border of the plains for which an excellent 
building stone was obtained from rocks of the Sivalik group, but it must have been found 
in detached blocks and discontinuous hands, the mass of the rock being quite unfit for the 
purpose. Stone fit for ornamental or monumental purposes might be found among the 
thick-bedded, hard limestones of the Krol group.”* 
Quartzites. 
The gradation from the loosest and most granular sandstone to the most intensely 
vitrified quartzite is so complete that it is impossible to draw a sharp line of demarcation 
between them. I therefore place the quartzites with the sandstones in this enumeration. 
Were the arrangement a purely geological one, a large portion of them would have to be 
classed with the schistose or gneissic rocks. 
If we except those varieties of the Vindhyan and Karnul sandstones which are some¬ 
times called quartzites, the use of rocks coming under this denomination has been very 
inconsiderable. Indeed the only instance known of a quartzite being regularly quarried is 
in the Susinia Hill in Manbhum. The works there were carried on for some years by the 
Burdwan Paving Stone Company, and large quantities of the stone have been used in Calcutta 
for pavings, copings, and other similar purposes. There are several varieties of this material 
found; in some there is a large proportion of felspar, when it should be called granulit 
rather than quartzite. 
Although these rocks have been so little used, the Bijaur or suhmetamorphic series, in 
many parts of the country, afford quartzites suitable for building purposes; wherever these 
occur in the vicinity of Vindhyan sandstones, the latter will naturally be preferred, as they 
are in most instances much more easily worked. The vitreous fracture of many quartzites 
is in fact a bar to their employment where much finish is required. 
IX.— Laterite. 
The term laterite has been applied generically to a group of rocks which play an 
important part in the superficial geology of India. The common character which persists 
throughout all the varieties of laterite is the possession of a ferruginous element which is 
in the form of brown hydrated peroxide on the surface, sometimes as the black magnetic 
ore inside. The reddish-brown appearance, due to the presence of the peroxide, explains 
the origin of the name ( later , a brick) which was, I believe, first conferred upon it by 
Dr. Buchanan. 
The various forms in which laterite occurs are due to differences of composition and 
differences of structure. The combinations of these two qualities produce almost infinite 
varieties. The principal structural varieties are either nodular or cellular, the former being 
the younger, and it is supposed, in a measure, derived from the latter. The varieties in 
composition vary much in the quantity of the peroxide which they contain and in the 
character of the other materials. Both classes pass off into mere detrital laterite, to the 
ferruginous element in which they have no doubt mainly contributed. 
* Medlicott, Mem. Geol. Surv., India, III, p. 175. 
