162 
MR. C. BARRINGTON BROWN AND PROFESSOR J. W. JUDD 
At No. 10 mine, near Dattau, in the ruby-bearing clay of a yellowish-brown colour, 
some of the pebbles are rounded, while others are angular. They consist of quartz 
and pegmatite, and lie at the base of the red hill wash. Amongst the minerals are 
flat plates of graphite, and in the clays above are large, clear mica crystals scattered 
through it. 
The length of the cutting at No. 1 mine, which is close to Mogok Stockade, is 
some 400 yards. The height and width of the face is 60 feet, composed of red 
loamy clay in its upper part passing downward into a brownish clay containing sand 
and gravel, in which are rubies, and a few sapphires, and other minerals. This rests 
on the serrated surface of the white and bluish highly crystalline limestone. In the 
brownish clay are small blocks of semi-decomposed pegmatite. 
On the south side of Mogok valley near Petswe is mine No. 9, the only one in 
operation on that side of the valley in 1888. It is a very extensive working in red 
loamy clay, having a depth of 28 feet at the face, containing mingled masses of water- 
worn blocks of pegmatite, ranging from small sizes up to 3 feet in diameter. These 
rocks contain garnets, and greatly resemble some portions of the crystalline limestone 
in outward appearance. The ruby-bearing clay at the base of the cutting is of a 
yellowish and brownish colour, and contains small blocks of semi-decomposed 
pegmatite. 
No. 13 mine is situated on the north side of the Yeboo (Yebu) at the base of the 
red hill wash, which is there in its lowest part mingled with great blocks and 
boulders of gneiss and granulite, the latter being of a coarsely crystalline structure, 
and of great size, some measuring as much as 20 feet in diameter. The gem-bearing 
portion consists of white waterworn quartz, gravel, and sand, and is deposited amongst 
and beneath the boulders on the uneven surface of coarsely crystalline limestone. 
Opposite Ivyatpyen, in mine No. 25, this deposit is composed of dark and light red- 
coloured loamy clay, amongst which are large waterworn blocks of gneiss and 
pegmatite. The face of the cutting is 30 feet high, and a pit has been sunk to a 
depth of 40 feet, in order to cut other layers of gem-bearing material, without 
apparently reaching the bed rock. This shows the great thickness of the deposit in 
this spot. Amongst the boulders, at the bottom of the cutting, is the ruby-bearing 
earthy clay of a brownish colour, which is mixed with a large percentage of exceed- 
ingly waterworn gravel composed of quartz and black tourmaline, amongst which is 
a quantity of mica. 
In the red clay face of No. 26 mine, which is close to but at a higher elevation 
than the last-mentioned mine, there are quantities of small angular chips of quartz; 
whilst in the gem-bearing clay beneath are numerous flat crystals of graphite, similar 
to those so frequently seen in the crystalline limestone. In neither of these mines is 
any limestone to be seen, although the narrow belt of that rock which passes through 
No. 1 mine should cross near their position. 
West of Pingu Hill, in No. 27 mine, which is a large cutting 25 yards long by 
