OCCURRENCE OF A NEW MINERAL AT BROKEN HILL. 371 
carbonate of lead into which it was being changed. Purest speci- 
mens crypto-crystalline, structure somewhat resembling argentite 
but very indistinct. Depth about one hundred feet; associated 
mineral stromeyerite ; lode-gangue limonite. 
Antimonial Silver Chloride—Silver chloride (or chloro-bromide) 
is of comparatively rare occurrence, considering the quantities 
found elsewhere on this field. A silver chloride has been found 
in large masses which differs from the ordinary chloride of the 
other mines, and in fact from any yet reported. This ore is 
always massive and antimonial; of a uniform grey colour and 
fairly constant value of about fifty-five per cent. silver. Some 
Jumps enclosed veins of the ordinary chloride, and others patches 
of dyscrasite ; some of the latter showed that it had undoubtedly, 
in my opinion, been altered from the dyscrasite. A specimen in 
my collection shows the antimonial chloride enclosing a kernel of 
unaltered dyscrasite, round the edge of which can be seen the 
chloride in the granular form of the other. A very interesting 
mineral deserving further attention and analysis. Associated 
minerals stromeyerite, bindheimite, azurite and volgerite ; lode- 
gangue limonite. Depth one hundred to one hundred and forty 
feet (vertical). A round lump (detached slug) of this mineral 
was found in a soft formation, and was coated with small crystals 
of ordinary chloride. <A large slug was unearthed before I came 
to the mine, and which I did not see, weighing four hundred and 
seventy-five pounds. These pieces were shipped to London intact 
and were presumably homogeneous. 
Bournonite—Antimonial lead and copper ore. Entered here on 
account of its high silver value. Occurs in limited quantity in 
upper portion of vein forming small bonanzas in limonite, often 
perfectly isolated from other ores ; always impure containing from 
about five to seven per cent. silver. Generally associated with 
various lead ores and malachite ; sometimes showing mechanical 
mixture with tetrahedrite from which the silver has doubtless 
been derived. An analysis gave a friend who kindly undertook 
to determine a specimen of this ore, the following :— 
