Report on the Geological Survey of Connecticut. 173 
thirds of the stone in working the quarry ; this stone is sold in Hart- 
ford at from ten to twelve cents the square foot.” 
“The quarries of Killingly have but recently been opened; and 
although highly promising in their character, are comparatively but 
little known to the public at large. The stone is altogether peculiar 
in its character. It is the micaceous quartz-rock, consisting almost 
exclusively of the species quartz. The mica present is nearly un- 
distinguishable, and would quite escape ordinary observation but for 
its hair-brown color. It is most obvious on the cleavage-surfaces, 
where it is seen collected together into clouded patches; but so 
small is its quantity on the whole, that it seems almost inadequate 
to account for the free and strait cleavages by which the rock sepa- 
rates, and yet no other cause can be adduced for their production. 
The mica sometimes has a yellowish tinge, in which case we have 
a rock so exactly identical in structure and appearance with the 
avanturine of Spain that samples of it are well worthy of being 
submitted to the wheel of the lapidary. The cleavages occur at 
distances, of from half an inch to four and six inches apart, and 
seem perfectly parallel often for ten or fifteen feet in each direction. 
The surfaces of the slabs are as smooth and even, as those of the 
best moulded tiles. In strength, it is not inferior to any other flag- 
ging-stone, if we except perhaps the hornblende-slate. It is not 
liable to disintegration from exposure to the weather, or from immer- 
sion in water. In these respects it surpasses in value the more mi- 
caceous slates. Judging from weather-beaten masses of the rock, 
it grows whiter on exposure; an effect resulting from the loss of the 
brown mica, which is more abundant on the BEERS surfaces than 
through the general mass of the stone. 
‘“‘'The uses to which this flagging-stone may be applied are nume- 
rous, and many of them quite new. Asa paving for side-walks it 
must be pre-eminently valuable, not only on account of the size of 
the slabs and their smoothness, but from the hardness of the mate- 
rial. The friction to which it will be subjected in this situation 
cannot it would seem, make the slightest impression upon it ; for its 
hardness is superior to that of the firmest and most imperishable 
granite. For this reason, flag-stones from this rock which have 
been long in use will not require to be roughened up with the chisel, 
as is the case with some of the softer mica-slates. In the paving of 
door-yards, warehouses and cellars, its value is equally obvious. It 
roust surpass all other materials also, for lining drains, water-sluices 
