I 10 
Mines and Mineral Statistics, 
Unrolled blocks of the bed rock are met 'witli in all the drift. 
In all three we find occasional minute crystals of selenite, pro- 
bably of very recent origin. 
During the process of extracting the diamond from tlie w^asli- 
dirt, the material is sized as it passes through the machines j but 
as it is hardly necessary to consider these sands and gravels sepa- 
rately, it will bo as well to consider their constituents merely, 
irrespective of tlie size, since they all contain nearly the same 
minei'als, although not in the same proportions ; but as the large 
pebbles and boulders ■which are removed immediately after the 
stuff is puddled do differ from the finer parts considerablj^, we 
shall take them by themselves. 
]?chljles and houhlers. 
These consist of masses of red, green, brown, and other coloured 
jaspers ; white quartz, common agate, black flinty slate ; fine 
sandstone, into which manganese and iron oxides have infiltered, 
leaving dendritic markings between the joints. Dtfany of the peb- 
bles arc also coated externally in the same way. Xodules of 
magnesite and concretions of limonite or brown iron ore, of con- 
centric structure, — some of the magnesite still showing the limou- 
ite in situ. Eollod masses of hard compact brecciated conglomerate, 
often containing much manganese in tl.c cement ; masses of sili- 
cified wood (but this is not very common), cacholoiig, and green- 
stone. The rolled masses of sandstone, and especially the argill- 
aceous sandstone, often assume long finger-shaped forms, and are 
accordingly termed “linger stones” by the diggers. The pebbles 
% 1 'C not jxdished, as at Mudgcc. 
The list of gems, stones, and other minerals accompanying the 
diamond, includes the following; — 
1. Tourmaline, or “jet stone,” of the miners, occurs as rolled 
prisms, usually from a i to inch long. They usually retain the 
trigonal section, but sometimes no trace of crystalline form is left, 
and they appear merely as more or less rounded black pebbles, 
often with a pitted suriace, totally unlike the usual appearance 
of toui'maline ; tiie blow-pipe decides their character at once, for 
they intumesco before it and in other respects answer to the well- 
known tests. These “ black jet stones” are im-ariably found with 
the diamond, and arc regarded by the miners as one of the best 
indications of its i)resence. 
2. Zircon occurs in small crystals of red and brown colours, 
also nearly colourless, but more commonly as rolled pieces of a 
brown shade. A cleavage plane is usually to be seen. 
8. Sapphire, generally in small angular pieces and usually of a 
pale colour; in many the blue tint does not overspread the whole of 
the fragment. The Eiiby is present, hut very rare. One fragment 
showed the fitces of an acute hexagonal pyramid and basal pina- 
