the
stone is made clearer. It is then enveloped in fine lime and burned
with rice chaff. It is cut for setting in rings, &c. With the
exception of the last, most of these are of an indifferent quality, and
their locality is unknown. Some writers have maintained that both the
emerald and beryl are found in Ceylon. The former, says Davy, is
certainly not found, and there is much doubt as to the existence of the
latter, most of those offered for sale being imported; and those said
to be found in the island being improperly so, as affording an excuse
for a higher price than that asked for those of the continent, which
are contemptuously called "coast stones."
Of
the garnet family three species occur in gneiss or granitic rock, viz.,
the garnet, pyrope, and cinnamon stone. The common garnet is abundantly
disseminated through gneiss in almost every part of the country. Its
crystals are in general indistinct, small, contain a large proportion
of iron, and are very apt to decompose. The best and most perfect
crystals of this mineral are in quartz rock. The precious garnet occurs
but in few places, and not in first-rate quality. It is contained in
hornblende rock at Trincomalee.
Cinnamon
stone, though an abundant mineral in this island, to which it
exclusively pertains, is found only in a few places, and chielly in the
Matura district. It occurs in granitic alluvium in small irregularly
shaped pieces, and in large masses of several pounds weight. Near
Belligam a large detached rock is partly composed of this mineral; the
other ingredients of the rock are felspar, tablespar, quartz,
hornblende, and graphite. "The thick jungle," says Dr. Davy, "round the
spot where this interesting rock stands, prevents a minute examination
of the neighbouring country;" but his opinion seems to be that this
rock had been detached from a vein or bed included in gneiss or
granitic rock in the hill above. Another mineral of a doubtful nature,
disseminated in small masses, occurs in many places, as at Colombo,
Mount Lavinia, &c. It is semi-transparent, and never crystallized,
and has the fracture and lustre of cinnamon-stone. It certainly belongs
to the garnet family, and is probably merely a variety of cinnamon
stone; from which it appears to differ chiefly in being of a redder
hue, and in this respect approaches pyrope.
The
zircon family is richer in Ceylon than in any other part of the world.
It is chiefly confined to the districts of Matura and Saffragam, more
especially to the former, and is indicated by the popular name ' Matura
diamond,' which is applied to its finest varieties by the dealers in
gems. Besides the well known species, common zircon and hyacinth, a
third species, massive, opaque, un-crystallized, and of a dark brown
colour, some specimens of which, from Saffragam, have been known to
weigh two or three ounces, has been also found. The natives are
completely ignorant of the true nature of zircon. The yellow varieties
are sold by them as a peculiar kind of topaz; the green as tourmaline;
the red hyacinth as inferior rubies; and the very light grey as
imperfect diamonds. All the varieties on sale are found in the beds of
rivers, or in alluvial ground derived from the decomposition of gneiss
or granitic rock. It is to be seen, however, in its original site in
these districts sparingly disseminated through quartz and schorl rocks,
or quartz and felspar with tablespar and graphite. The zircon in some
parts of the mass so largely preponderates as almost to entitle the
rock to be called zircon rock. The mineral in such a case is
crystalline, and most commonly green or brown; the rock is remarkable
for its heaviness, and for the resinous lustre of its fracture.
For the ruby family (Lankarette Singh.), Ceylon
is no less celebrated. Four species of it, spinel, sapphire, corundum,
and chrysoberyl occur in gneiss or granitic rock. Spinell is
comparatively rare, though there are some small and most beautiful
crystals of it found in the interior, and it is found in specimens of
clay iron-ore in parts of the Central Provinee, where gneiss prevails.
Sapphire is common though widely scattered; it occurs in great
perfection and in considerable abundance and magnitude in the granitic
alluvium of Matura and Saffragam, and about Nuwara Eliya ; the
principal varieties being the blue, purple, red, yellow, white and
star-stone. Barbosa remarks that the Singhalese in his