BRITISH ORES. 
67 
Case 2. — Well known from its employment sometimes for 
ornamental purposes, and sometimes as a pigment, the beautiful 
mineral called Malachite or green carbonate of copper, naturally 
claims attention. In this country, however, it is found only in 
subordinate quantity. Its recent formation is illustrated by the 
specimens from Wheal Leisure, in which particles of sand from 
the sea-shore are cemented by this mineral. With these speci- 
mens may be noticed the examples of cupriferous sandstone and 
conglomerate from the Lower Keuper of the neighbourhood of 
Alderley Edge in Cheshire. Among the carbonates of copper 
will be found a few specimens of Azurite or blue malachite , and 
on the same shelf are some samples of Ghrysocolla, or hydrous 
silicate of copper. 
In the series of arsenates of copper from Cornwall, atten- 
tion may be directed to the beautiful sky-blue octahedrons of 
Liroconite ; the dark blackish green crystals of Glinoclase ; the 
bright emerald-green six-sided plates of Gopper mica ; the dull 
green crystals of Olivenite, and the fibrous variety of the same 
species known, from its structure, as wood arsenate of copper ... 
With these are associated some specimens of Libethenite, or- 
phosphate of copper, and a sample of the basic sulphate of copper 
from Cornwall, described by Professor Maskelyne, under the 
name of Langite. Here also will be found specimens of 
Professor Church’s Woodwardite, an uncrystallised mineral of 
fine blue colour containing sulphate of copper and hydrate of 
alumina. 
From these somewhat rare minerals we turn to the important 
ore, known as Gopper glance, vitreous copper, or Redruthite, a 
disulphide of copper containing 80 per cent, of metal. From. 
St. Ives and St. Just several fine crystallised specimens are 
exhibited, and in some of them will be recognised the peculiar 
six-sided forms which have suggested the popular name of 
“ nailhead copper ore.” 
Cases 3, 4, 5, 6. — Far exceeding all other copper ores in its. 
importance to this country is the well-known copper pyrites , — 
the yellow ore of the miner, and the Ghalcopyrite or Towanite of 
the mineralogist. This mineral, which is a sulphide of iron and 
copper, is usually found massive, but occasionally occurs crytal- 
lized, its characteristic forms being well shown by the specimens 
in Cases 3 and 4. The fine mammillated and botryoidal masses 
from Cornwall and Devon are known to the miners as “ blister 
ore ” ; whilst the iridescent tarnish on the surface of other 
varieties of copper pyrites has suggested the name of u peacock 
ore.” 
Case 7. — Allied in chemical composition to copper pyrites., 
with which, indeed, it was long confounded, is the species called 
Bornite, purple copper ore, or erubescite. To our Cornish miners 
the mineral is commonly known as “ horseflesh ore,” whilst 
frequently it passes under its German name of Buntkupfererz 
(variegated copper ore). 
