1 
104 
opinion that the elasticity of the stone is due to the presence 
of mica is erroneous, for on close microscopic examination of 
a slice of the rock it will be seen that the flexibility depends 
upon the minute articulation where the sand grains inter- 
lock.” “ In my specimens,” sa^^s Capt. Burton, “ the stone 
abounds in light yellow mica, and when the friable material 
crumbles the two main component parts at once separate. 
Near Sao Thome das Letras there is a fine quarry of this 
elastic sandstone. In the deeper parts the strata become 
thin, and gradually pass into natural slabs of the flnest 
quartzite, losing all elasticity. This flexible stone is not 
the matrix of the diamond and topaz, though sometimes 
associated with it.” 
A description of the Delhi flexible sandstone will be 
found in “ The Records Geological Survey of India, vol. vii., 
p. 81, by H. B. Medlicott, A.M., F.G.S,” of which the fol- 
lowing is only an abstract : — 
“The locality for the flexible sandstone is at Kaliana, 
near Dadri, about 60 miles due west from Delhi. The hill 
is 1,477 feet above sea level and 740 above the plain; it is 
a double-crested ridge from the Punjab. 
“ The projecting ribs on the double crest are formed of 
quartzite and strong ironstone bands, black hsematite 
chiefly. These ferruginous bands are regularly interstra- 
tifled with mica and hornblendic schist and an earthy 
cellular quartzite much quarried for millstones. All the 
strata are nearly vertical. 
“ The flexible sandstone is only found in patches in this 
millstone quartzite, there being no regular seam of it. The 
stone-cutters come upon it suddenly when cutting out 
slabs of the ordinary stone ; often the rock in immediate 
contact with a nest of the flexible stone is highly indurated 
and quartzose. It is found both in the bedding and in the 
joints. The quarrymen’s idea of the flexible stone is, that 
it is a mere local peculiarity of the sandstone rock caused 
by the percolation of rainwater and earth from the sur- 
face and Mr. Medlicott thinks that the water expla^iation 
is the correct one. 
