BY EDWD. B. LINDON, A.R.S.M. 53 
Mr. Enright, a miner who worked the claim, tells of a very 
decomposing pyrites—which I take to have been marcasite—from 
the Havelock mine, near Charleston, about too miles from 
Georgetown ; the ore was found in this state above and, as far 
as was worked, below the water-level, and was so soft that it could 
be pulled out with a pick and handled with a shovel like gravel. 
It was valued at 3 ozs. of gold to the ton, but the gold was 
exceedingly fine and difficult to obtain from it, ordinary washing 
producing but a very small ‘ prospect.” 
Mr. R. L. Jack, in his ‘‘ Geological Observations in the North of 
Queensland, 1886-7,” writes, “Some of the mines in the granite 
country have a mundic very difficult to treat with the ordinary 
appliances. For instance, in the Nil Desperandum, where the 
mundic consists of pyrites, arsenical pyrites, copper pyrites (some- 
times coated with sulphate of copper), a little galena, and a little 
zinc blende, the mercury is said to have been sometimes stripped 
from the plates in five minutes, and iron is coated with copper. 
In the Balmoral mundic which consists of iron pyrites, arsenical 
pyrites, and galena, I detected on weathered portions a considerable 
quantity of free sulphuric acid. This mundic corrodes shovels, 
screens, stamper boxes, Xc., in a short time. Better results might 
be obtained by running the stone through the stampers fresh from 
the mine, and before the acid has time to be set free by the 
weathering of the mundic.” 
MISPICKEL 
ARSENICAL Pyrites—Comp. Fe (As, S),, but often 
containing other metals. 
Arsenical pyrites is found in varying quantities in some of the 
tin mines of the Tinaroo district, as the Great Northern P.C., 
True Blue, Ulster, and Stewart’s T claim. It also occurs sparingly 
at Stanthorpe, being sometimes accompanied by molybdenite. 
On the Hodgkinson goldfield mispickel accompanies auriferous 
galena in quartz; it is also found associated with auriferous 
sphalerite and pyrite on the Buck Line at Ravenswood; with 
auriferous iron pyrites in quartz on Charters Towers and the 
Norton field, and in the Allendale lode, Chowey Creek, it forms 
part of an auriferous ore with iron pyrites, galena, and sphalerite. 
At Mount Witty, near Beenleigh, a hard-looking quartz contains 
arsenical pyrites which is auriferous, gold becoming visible on the 
decomposition of the mispickel. Also at Toowong, near Brisbane, 
arsenical pyrites in some quantity was met with in sinking a well, 
but I have not yet ascertained whether it is auriferous. 
