others are fpotted, partly blue, partly green, with all the
gradations and tints from the fky blue to the lapis lazuli,
£nd from a light, to the deepeft green. In fome parts the
aperture of the ftone is totally filled, and forms a body
equal to. the breadth of the fiifure ; but whatever be the
fize, it is always compofed o f parallel lamina, as thin as
an eggiheD, and fucceifively depofited one over the
other, by the water, which makes it indubitable, that this
mine is alluvial; firft formed by the decompofition of the
rocks, their recompofition. and. moifture..
This lamellated metal is compofed o f various plates,
which I call primeval, fome are chequered with fmalt
hollow round.grains, hardly feen with the lens, which I
conceive are formed by bubbles o f air, at the time, of the
decompofition o f the rock, and the. forming the driveL
o f the metal. Thefe bubbles imprefs their figure on the.
lamina above, and occafion thofe beautiful, grains, from,
whofe variegated waves in the concentrical lamina,, re-
fults that beauty of colour in the ftone, when poliihed,.
which furpaifes thofe of the eaft, and would ftand unrivalled,
were its. hardnefs, equal to the peculiarity o f
its ihades.
Having examined one of thefe lamina, of a line in thick-
nefs, I found it to confift of three and twenty leaves,
the white calcareous earth was formed by the drivel of
the
the copper, at the inftant of decompofition, and always
follows it, covering the ore, as well in the green, as in
the blue, and yellow, and when this white earth abounds,
then the green ore is. of a very pale hue. Breaking a-
piece of the ore, fiffures are feen in the 'Centre full of a
green or yellow matter, and i f there is any cavity, there
are,final 1:blue cryftals,like fragments of fapphiresothers,
green like, emeralds, and true rock O cry' ftai, blue, or
green («), I broke one of thefe cryftals that was fixed
in the hollow part of a rock, and was folid without. It
was as green as an emerald, in the centre, without the
leaft appearance of crack, or crevice, exteriorly ; which I
put into an acid, when all the green matter diffoived,
and the cryftai remained perfed and entire, except a
finall cavity in the centre. To explain the forming of
this cryftai, it is neceffary to fuppofe, thatthe copper and
calcareous earth were formed by the decompofition of
the rock, by fome interior labour, and that the limy part
mineralized the copper, and covered its atoms, without
any communication of acids, fixed or volatile alkali, ful-
phur or arf?nic, for the matter being calcined does not
yield any fmoak, neither emit a fulphurous fmell, anil cx-
pofed to the air many years, does not decompofe, acquire
tafte, or change colour.
’ Mr. Bowles fays, that they are not fapphires, nor emeralds, as thofe two Bones ’ will
diflolve in acids; l¡a fait which Cannot be admiltefj-like the green or blue tolhnring parts o f
rock cryftai, and that thofe o f this mine w ill not dilíolve.— Introducción a la hift. nat. 8ec,
‘ 97- ! ’ When