ORIGIN OF THE DIAMOND.
The origin of this precious stone has been a favorite study with man
from the earliest times of its history; and, as we have already stated,
it has given birth to a multitude of hypotheses.
The peculiar fascination which attends the contemplation of the gems
arises partly from their commercial distinction, as well as from
certain mysterious properties with which they have been invested not
only by tradition but even by scientific research.
We will not, however, venture to affirm that they are more wonderful or
deserving of a higher place in the estimation of man than the beautiful
and more transient flowers of vegetation. Both are indeed objects of
our highest consideration.
The transparent diamonds always occur in crystalline forms, although
they sometimes appear almost amorphous or even cylindrical or globular.
Its primitive form, however, is the octahedron.
They are found generally in limited deposits, which are often as
shallow and well defined as the gold fields, which are termed placers;
and therefore we will also call the diamond fields “diamond placers.”
In some “placers” the shapes of the crystals are perfectly regular,
while in others they are greatly modified and rendered indistinct. In
some mines they occur in fine octahedrons with beautifully truncated
edges, but in other districts the rare form of the regular cube may
abound. Every section of the diamond-bearing countries seems to have
some peculiarity either in color, form, or arrangement of crystal. It
is indeed true that experts, from an examination of the rough specimen,
are sometimes able to detect the locality whence the diamond was
obtained. The same facility may be applied to the natural crystals of
other gems, but it cannot be established as a fixed or general rule.
The diamond “placers,” distinct and well defined, are far more numerous
on the earth’s crust than is generally believed.
A thousand plausible and often ingenious theories on the geological
character of the diamond have been advanced in modern times or within
a century past; and a great variety of rocks or mineral substances
extending from itacolumite to xanthophyllite have been affirmed to be
the parent mineral. The real matrix, or such as we believe it to be,
of the diamond is the same all over the world. The associate minerals
which form the conglomerate in which it is generally found may vary
somewhat, but the character of the deposit is but little changed. This
matrix is a secondary product, and consists of a conglomerate gravel
which once abounded in remains of animal and vegetable life.
The keen eye of Buffon early detected the formation of the true gem
strata; and believing that the gems were produced in these peculiar
beds by the solar forces, he boldly asserted that they were formed in
the superficial strata from _débris_ of older formations, mineral,
animal, and vegetable. “On ne peut leur donner d’autre origine, d’autre
matrice que la terre limoneuse qui rassemblant les debris des autres
matieres.”
This matrix is a well-defined conglomerate, which is found generally
on elevated plateaux, and which corresponds to the bottoms of shallow
lagoons or lakes of inconsiderable depth. In the earthy portion, which
is composed of a variety of _débris_, occur the diamonds, interspersed
among the quartz or rock pebbles, and in a marked and continuous layer.
These formations are well known to the geologist, for they occur in
almost every country on the globe.
In various parts of the earth’s structure we find solid strata
of conglomerate and sandstone, which have been formed at distant
and different periods of the world’s history. In other places we
may observe the loose materials of the same formation awaiting
transformation when exposed to the action of water highly charged with
iron, lime, or silica, and we may even see the process taking place at
the present day. For example, we will take the broad tracts of level
country known in the south of France as the “Landes.” Here we have an
excellent illustration of the formation of the gem beds, lacking,
however, the precious stones. Below the surface of these plains, and
generally at the depth of about three feet, a conglomerate called
“allios” has formed, and is still in the process of forming. This stony
layer, which is composed of quartz pebbles mixed with sand, has been
cemented strongly together by the vegetable and organic matter which
has trickled down from the surface of the earth during indefinite
periods of time. The action of this organic _débris_ soon renders the
conglomerate quite impervious to water, and retards its passing into
the sand beds or other strata below. In consequence thereof these broad
tracts of level lands become stagnant lagoons of water during the rainy
seasons, and all the remains of vegetable and other organic life sink
down into these layers of stone, gradually filling up the interstices
among the rocks and lesser pebbles.
This collection of decayed various organic substances is generally
of a gray or blackish color, or may be of a rusty yellow-hue like
ferruginous sandstone. Its cementing power has given a special name
to the formation it has caused; and to the gold-miner it is known as
hard-pan, to the gem-seeker as cascalho or “mellan.” Its peculiar hue,
together with the metallic fracture of its layers, has given rise to
the belief that it was composed chiefly of a ferruginous oxide. Recent
analysis, however, of the “allios” has shown that this idea is partly
erroneous, and that the color and the substance of the formation
in reality arises from the juice and _débris_ of plants loaded with
tannin and other matter. Iron, it seems from these investigations, is
present only in small quantities, and also is afforded by the secretion
of vegetable life. However, the quantity of iron in the conglomerate
varies considerably in different localities, but most of it seems to be
acquired from the action of vegetable vitality.
These conglomerates of the Landes have been a long time in process of
formation; but in other localities, like those of the Cape de Verde,
to which the waves of the sea have had access, we may witness the
transformation going on with rapidity. No great time is required by
nature for this production, but rather the application or conjunction
of certain materials exposed to the action of chemical changes and
telluric forces.
It has been asserted that the diamond has been found embedded in
the singular quartzite to which Count D’Eschwège gave the name of
itacolumite, but we are inclined from examination of one of these
specimens to think that its presence is quite accidental.
In the State of Georgia there are immense beds of itacolumite,
appearing, also, here and there along the auriferous formation which
extends from Virginia to central Alabama; and they afford ample fields
for proof of the statement that the mineral is really the true matrix
of the gem. But, after careful examination of some of these exposed
rocks, we are led to regard the itacolumite as an associate mineral
to the diamond, and that any farther connection with the gem is very
distant. Fragments of this rock are quite often found together with
quartz in the conglomerate; but we do not regard their presence
as essential as that of a ferruginous oxide, which is one of the
distinguishing features of all gem mines, and especially of the famous
deposits of Ceylon, where the diamond is never found.
The best and most characteristic mines of India, Brazil, and Africa are
situated on elevated plateaux, where there is at present but little
vegetation.
To give the reader an idea of the formation, we will describe one
of the districts of South Africa, which may serve to illustrate all
others. At Pnict Kopje, in the Vaal region, the diamonds are found
on an elevated plateau one hundred and fifty feet above the river
bed; and many of them have been discovered but two or three feet
below the surface, in company with fossil wood and even bones. In the
Orange River Republic they occur frequently in peculiar isolated and
circumscribed spots, called by the miners “pans.” These are basin-like
hollows which are filled with water during the wet seasons. In these
pans none of the diamonds exhibit signs of abrasion caused by shock
or attrition, although the quartz pebbles forming the gravel and
conglomerate show in their rounded angles evidences of aqueous action.
The gems are not only found in the shallow edges of these hollows,
but are taken from depths of one hundred feet and more. And they are
always found in their peculiar and connected conglomerate, which seems
to have formed at the bottom of some pool or lake. Hence we may explain
the superficial depth of the cascalho at the shores of the extinct
pond, and the increased depth at central parts of the fields. If motion
had taken place among the pebbles forming the conglomerate after the
deposition of the diamond, we might properly look for worn surfaces on
the gems from shock with contact with loose rocks; for slight blows
will mar the surface of the diamond, even if its edges scratch all
other minerals with perfect ease.
In these pans the diamonds are natural in form, indicating that they
have not moved since the time they were deposited. But in the beds of
the rivers which have in later times worn deep ravines in the face of
the country we find diamonds with abraded surfaces, having been rolled
about by the torrents for indefinite periods of time. Whence come the
alluvial soils and the gravel beds which cover the gem strata and
completely fill up the lake depression, especially when there are no
surrounding elevations to furnish disintegrated material?
This serious question will naturally arise in the minds of all
observers; and to answer it clearly will be a difficult task. Sometimes
the thought occurs to us that much of the quartz gravel has formed in
these pools at subsequent periods and has been broken up and rolled
about by the waves until another stratum of alluvium has formed above
it; but we will not venture to assert an opinion to this effect.
Still, it is a great mystery to ascertain whence some of the quartz
pebbles came from in the present elevated condition of the placers and
the absence of similar rocks in the vicinity. There is another fact
connected with the diamond placers which deserves consideration, and
that is their great elevation above the sea level.
The mines of India, Africa, and Brazil are situated at a considerable
altitude above the ocean. Those of India are generally a thousand feet
above the sea level; while the wonderful gem mines of the adjacent
island of Ceylon, which are also true placers, occur but few feet above
the line of the tides, but do not yield the diamond. It is certainly
remarkable that Ceylon does not afford this gem among the great number
of other precious stones. At first thought the idea occurs to the
observer that as flora and fauna have their distribution according to
certain elevations a similar rule may be applied to the deposition of
minerals. But there are too many exceptions known to oppose this view,
however pleasing the theory may be.
One of the strongest arguments in favor of the theory of the recent
deposition of the gem is connected with its discovery in the gold mines
of the Adolfskoi in Siberia. Here they were found in alluvial strata
twenty feet above those deposits which contained the bones of the
mammoth and the rhinoceros. Hence Humboldt, Murchison, and Verneuil
were led to the conclusion that they had been deposited there since the
introduction of animal life. There are also some remarkable evidences
to sustain the view that these gems were formed in the conglomerate
and earth where they are now found. In some of the mines of India they
have been taken out of red earth with the earth clinging to their
sides as if it had become attached to them, while the crystals were
of a soft, glutinous substance. In the Museum of Rio Janeiro there is
a large rounded diamond which has very distinct impressions of grains
of sand upon its sides. The British Museum contains an octahedral
crystal attached to alluvial gold, and Dr. Nello Franka mentions
another which enclosed a leaf of gold. A number of specimens have been
observed containing splinters of ferruginous quartz and crystals of
other substances. The microscope often reveals in the interior of these
stones germs of fungi and even vegetable fibres of higher organization,
some of which resemble the moss-like appearance seen in the moss agates.
It was from the study of these conditions, connected with the fact
that the stone becomes black when strongly heated, that Goppert was
led to assert that it could not be of igneous origin. It was also
from investigation of the refractive powers of the gem that Sir David
Brewster was induced to assume the hypothesis that it was, or that
it might be, a congealed secretion of a vegetable production. This
distinguished philosopher was seeking a perfect lens for microscopic
use; and discovered that the diamond, notwithstanding its immense
refractive power, was of very doubtful character in its adaptation
to this purpose, and that its laminæ were sometimes of different
shades and even arranged in a series of stratification. They not only
differed from each other in color and purity, but did not exhibit a
common focus. Therefore, Brewster was led to infer from these and other
phenomena that the mineral was of vegetable origin, and that its parts
must have been held in solution before crystallization took place.
There is nothing very startling in this hypothesis, no more so than
in the case of the amber, which is now admitted to be a fossil resin,
and which is, in its refractive powers, second only to the diamond.
Therefore we cannot object to the theory of vegetable origin on account
of the property of brilliancy.
Tavernier observed that the color of the diamonds in India
often partook of the color of the gravel in which they were
deposited,--white, reddish, blackish, or greenish, according to the
color and purity of the matrix. This fact has also been noticed in
Brazil; and it lends support to the view that the gems have been
deposited under stagnant water, and have received some tinge from its
color.
The diamond is admitted by microscopists to be one of the foulest gems
known to them; and specimens are rare that do not exhibit cavities,
imperfections, or foreign matter in their interior. A painstaking
microscopist, after examining the large collection of rough crystals
of the East India Company in London, which numbered several hundred
specimens, came to the following conclusion: “It seems to be a general
truth that there are comparatively few diamonds without cavities and
flaws, and that the diamond is a fouler stone than any other used in
jewelry.”
Berzelius first called attention to a black substance which he found in
a diamond belonging to the collection of Countess Porlier; and since
then many other examples have been observed. Frequently black specks
resembling anthracite have been noticed in the Brazilian diamonds.
Tavernier saw in India a large diamond of one hundred and four karats,
whose central portion was so foul as to render the stone worthless.
When it was cut open the cavity yielded about eight karats of filth,
resembling that of a rotten weed.
The diamond is now recognized by the chemist as a crystalline form
of pure carbon. Newton, in 1675, with the wonderful penetration of
his genius, and reasoning from the high refractive power of the gem,
which so far exceeded the degree due its density, believed it to be
combustible. More than a century later the experimentalists of the
Academy of Florence strengthened this view by destroying it in the
focus of powerful burning mirrors. Lavoisier, however, dispelled
all doubts concerning its combustibility by burning it under a
receiver filled with oxygen gas. It has since been ascertained that
a temperature of 14° Wedgewood completely volatilizes the diamond,
producing carbonic acid gas. An English experimentalist, however, has
recently declared that the gem may be consumed at a red heat, and
maintains that he has accomplished this result by enveloping the stone
in certain alkalies.
It has been admitted by eminent geologists that the diamond proceeded
from the slow decomposition of vegetable material, and even animal
matter, as the requisite carbon could be obtained from either source.
But they have also strenuously maintained that the gem was formed
under the same conditions of heat as produced the metamorphism of
argillaceous and arenaceous schists, these schists being supposed
to have once been altered from shales impregnated with carbonaceous
substances of organic origin. To this theory the revelations of the
microscope offer decisive objections, since this instrument shows that
there has been no action of heat in the formation of the stone, for the
vegetable remains often detected in the interior of the mineral forbid
the development of any considerable degree of caloric. Therefore, as
there is no evidence of the influence or effect of heat upon these
organic matters within the diamond, the theory must be abandoned.
Geologists have been, perhaps, too tenacious in their views of the
origin of many of the rocks that compose the earth’s crust, and
especially in maintaining that many crystalline rocks are as old
as the dawn of creation. We know that some of these minerals may be
produced artificially at the present day, and that the forces that
arranged all rocks of a high molecular organization are still in force.
We sometimes speak of old crystalline rocks with the inference that
their age is beyond comparison, and therefore undetermined. Yet
the microscope is constantly lessening the force of these views by
revealing prodigious numbers of minute and animal forms in fossil
condition in various kinds of crystalline rocks.
We also observe that various forms of silex have been deposited on the
earth in recent periods of its history, and even since the appearance
of animal life, for we find their remains transformed into agate. Thus
it is evident that nature still possesses the power to deposit certain
forms of mineral substances.
Arago and Biot, reasoning from the energy of the refractive power of
the diamond, were inclined to believe that it contained hydrogen. Sir
Humphrey Davy suspected the presence of oxygen, but sought for it in
vain after many careful experiments. Chaucourtois, however, deriving
a theory from chemical results, came to the view that the stone is
derived by the humid process from a hydrocarburet. Reasoning from the
process of forming sulphur from hydro-sulphuretted emanations, he
believed that in the humid oxidation of a carburetted hydrogen the
hydrogen is oxidized, while part of the carbon becomes carbonic acid,
and the rest remains as carbon and may crystallize into diamond.
Supposing this hypothesis to be correct, where do you find the required
materials for the formation of the diamond? the reader may ask. At
the bottom of these lagoons the decomposition of organic matter
furnished abundant means for the production of the gem. Carbonic acid
is everywhere produced from the decomposition of animal and vegetable
matter. It is constantly evolved from the earth, and has the property
of decomposing many of the hardest rocks. It is the cause of that
mysterious decay which Dolomieu called “La maladie du granite.”
In carburetted hydrogen we have the united force of two of the most
active substances known as organogens, or generators of organic bodies.
But of the vast range of their properties, their affinities, and their
interior changes we are still profoundly ignorant. We may, however,
easily recognize the fact that their combinations and also almost every
other chemical compound may be decomposed by electricity or galvanism.
Here then we have a clew, though perhaps distant, to the formation
of the gem. Is not the production of drops of water by passing the
electric spark through a mixture of hydrogen and atmospheric oxygen
suggestive of the manner in which the diamond might be formed from
carburetted hydrogen? It is true this experiment in the laboratory
has failed to produce the transparent and crystalline form of carbon,
although it has thrown down the element in an amorphous state. This
failure is by no means decisive, for many of the simple acts of nature
are beyond the imitative power of man.
And then again the chemist may exclaim, “How is it possible for the gem
to be produced in this manner, when the combination of these elementary
bodies is always or nearly always attended with the development of a
considerable degree of heat, while the diamond contains at times germs
of organic matter? Would not these organic remains be destroyed during
this process? On the contrary, they do not exhibit the least trace of
the effect of combustion or even heat, and are as well defined as the
insects in the fossil resins.” In reply we will point to the formation
of fulgurites through the agency of the lightning without the evolution
of heat.
History presents some almost incredible examples of the stupidity and
obstinacy of mankind in the explanation of natural phenomena. It seems
quite impossible that when the German philosopher Chladni, less than
a century ago, asserted that meteorites were extra-terranean bodies,
the Academies of Europe laughed at him in scorn. Several meteoric
showers falling in Europe shortly after did not convince the bigoted
philosophers. And when Pictet in 1802 read a paper before the French
Institute in favor of the theory, he was insulted by his learned
audience. It was not until a year afterwards, when the great meteoric
shower occurred in Normandy, that Biot, deputized by the French
Government, succeeded in convincing the most sceptical. Yet only a few
years previous De Luc, the first meteorologist of Europe, the founder
of geology, declared that he would not believe it even if a stone
should fall at his feet from the skies. In 1751, Peysonnel presented
to the Academy of Sciences at Naples an elaborate memoir in which he
very plainly proved that the coral belonged to the animal and not
the vegetable kingdom. But his admirable paper was hooted at by the
European naturalists; and even the distinguished philosopher Reaumur
declared that the idea which was advanced was really too absurd to be
discussed.
When we come to review the hypotheses of science during the last
century, we shall feel more inclined to be generous and flexible in our
views of natural phenomena.
“There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy.”
The nodular or globular forms of the gem present no serious objection
to the idea of vegetable or animal origin; and we may refer for
argument to the calcareous nodules of the old red sandstone. These
concretionary and radiated masses are merely sarcophagi of animal
remains; and their arrangement plainly shows the chemical influences
of decaying animal matter and also the multiple and varied effect
of crystalline attraction and electric force. Can we say that the
crystallized diamonds occurring in well-defined placers are any
more remarkable than the little globular petrifactions found in the
cretaceous formation and known as the _Coscinopora globularis_, and
which nature provided with a perforation so that ancient man adopted
them as ornaments in place of beads?
We are often reminded by the antiquary of the remarkable foresight or
acuteness of the ancient poet Lucretius in his explanation of certain
natural phenomena which have since been verified by modern science. But
of all the heaven-inspired dreamers none have come nearer the truth in
terrestrial matters than the Arabian poet Fizee, who wrote:--
“The sun from whom the seven seas obtain pearls,
The black stone from his rays obtains the jewel,
The mine from the correcting influence of his beams obtains gold.”
Plato believed that the gems were produced by a sort of vivifying
spirit descending from the stars. It is undoubtedly from the influence
of the solar forces and the magnetic and electric currents which are
constantly playing through the crust of the earth that the gems derive
their origin.
These phenomena of the earth’s vitality are manifested in their
greatest force along certain elliptics, which may be traced over the
true gem districts of Asia, Africa, and Brazil, and in marked contrast
to adjacent territories. The miners in South Africa, disturbed by the
severe whirlwinds and frequent thunder-storms, soon began to imagine
that the excessive electric action had something to do with the
creation of the gems they sought. Mr. Voysey, Geologist to the India
Survey, also observed the very marked telluric action in the diamond
formations of India, and moreover that the process of crystallization
took place there with wonderful rapidity. So convinced was this
keen observer of the present reproduction of gems in the alluvial
soil or conglomerate that he commenced to collect the proofs of
recrystallization. Unfortunately for science, Mr. Voysey died shortly
after he adopted these views. Dr. Buchanan, another traveller who
visited many of the mines of India, was impressed with this idea; and
he was assured by the miners all over India that the regeneration of
diamonds is always going on in the peculiar gravel. In proof of their
statements, many men were then engaged in working over the _débris_
that had been examined many years before. An interval of fifteen years
was sufficient in their estimation to reproduce new gems, at least to a
certain extent. This reproduction, or rather, we will say, assertion of
a reproduction, reminds one of the mysterious action of the nitre beds,
which yield rich returns after a rest of a few years, and especially
those which occur among rocks which are destitute of potash.
It is to the learned Abbé Haüy we owe the theory that crystals are
made up of an assemblage of minute parts or molecules, each having the
same definite form. To the diamond especially this hypothesis may be
applied, since it is composed of thin laminæ covering or concealing
its primary form. With the aid of the skill of the artisan we can
remove these coverings one after the other, until the definite and
elementary form of the crystal be revealed. In the time of Louis
XIV. it was thought that the size of diamonds might be increased by
placing them in certain solutions, as crystals of salt are enlarged by
immersing them in solutions of the same substance. But the difficulty
then was to find the required liquid; and even at the present day we
have not yet succeeded in discovering the composition of the water of
crystallization of crystals of quartz or topaz, although Nature has
shown the fluid to us in the cavities of certain crystals.
These curious speculations which were discussed in the days of the
“Grand Monarque” are again revived by the theory that gold nuggets are
not only deposited from aqueous solutions, but are actually increasing
in size under certain influences and conditions.
But where does this metal come from? the inquirer may ask. From a
variety of sources, we may reply. Does not the water of the ocean
contain it in appreciable quantities, and did not M. Sage extract
it from the ashes of certain burned vegetable substances? We also
know for a certainty that iron is produced by vegetable vitality, but
we will not attempt to explain the manner or whence the material is
primarily derived. Cosmic dust or the invisible atoms of the atmosphere
may be the source. The origin of the gold nuggets and the particles of
gold-dust in the well-defined placers, as advanced in the hypotheses of
Raymond and Murray within the past few years, is connected very closely
with the theory of the recent formation of diamonds in similar placers.
In connection with this theme, it is proper to make a digression in
explanation of the condition and formation of the gold placers, as they
seem to be highly suggestive of the depositions of the diamond placers.
Gold is often found in the same strata with the diamonds, and the
presence of the one sometimes indicates the deposition of the other.
But this is not invariably the fact. Yet the peculiar formation in
which the metal and the gem occur leads the geologist to similar trains
of reasoning when seeking to explain their presence in the tertiary
strata of very recent times. It has been generally supposed that all
alluvial gold is the result of disintegration of the old crystalline
rocks. But we now distinguish placer gold into two kinds, as the
alluvial and that which results from decomposition of quartz reefs.
The distinction between these two qualities of the same metal arises
from differences which are quite strongly marked. The alluvial gold is
generally much purer than the reef gold; and the reefs rarely, if ever,
contain nuggets. The appearance of the nuggets and particles from the
true placers, in comparison with the gold-dust evidently set free by
aqueous action, is suggestive of a theory that they have been deposited
by different agencies.
It has been suggested by Mr. Selwyn, the Government Geologist of
Victoria, while studying these differences, that the gold nuggets found
in the drift may have been deposited from solutions containing gold by
means of electric and chemical agencies. Mr. Skey, analyst to the New
Zealand Geological Survey, has recently come to similar conclusions
from his researches on the subject. The theory is well illustrated by
the formation of crystals and masses of iron pyrites from solutions of
that metal; and as gold is often found associated, free and uncombined,
in these pyritiferous depositions, there is sufficient evidence to
believe there may be some connection in the manner of formation.
From the results of certain chemical experiments in the laboratory,
it would appear that organic matter is one of the necessary chemical
agents for the decomposition of some of the solutions of gold.
Therefore, if we assume this hypothesis to have a positive bearing
upon this question, the abundance of organic matter occurring in the
gravel beds adds to its weight as an argument. Selwyn found in the
gold-bearing drifts of Australia quantities of fragments of wood,
roots of trees, and other organic _débris_ to serve as nuclei, or as
reagents for the reduction of mineral solutions. We may introduce as
evidence the formation of iron pyrites in crystalline forms, which is
taking place at the present day under the action of sea-water. The
metal in these instances replaces the organic structure of wood, or
assumes definite forms with a particle of organic matter as a nucleus.
The formation of gold nuggets from solutions of the metal is by no
means as wonderful or difficult of explanation as some other phenomena
witnessed in metallurgy. The strange play of pseudomorphism is well
defined in some instances, if not well understood. Here we observe
that the peculiarity of form may be rigidly adhered to, while the
composition is completely changed. In the waters of certain copper
mines, drills, rings, and bars of iron that have accidentally been left
have in course of time become transformed into pure copper. The iron
of the implements has changed places with the atoms of copper held in
solution.
In connection with this interesting theory, there are some puzzling
facts to be deduced from the phenomena of the auriferous sand beds
of some of the rivers of Europe. The gold placers along the coast
of the Danube and the Rhine are situated far from the mountains,
the supposed sources of the metal, and there are also wide barren
districts intervening. The river Tesino affords no gold in its sands
until its waters have passed through and beyond Lake Maggiore. From
these and other examples, it is quite evident that the gold which
appears in these river beds has been derived from the placers through
which the rivers have passed, and not from quartz reefs in the distant
mountainous regions. The situation of these placers, with the evenness
and regularity of their deposits, also the absence of auriferous ledges
among the contiguous rocks, permit the observer to indulge in the idea
that the gold may have been deposited from solutions and not from
the decomposition of crystalline rocks. We certainly have sufficient
evidence to object to that final explanation which ascribes all these
depositions to aqueous action in distant times, and to the abrasion
of primitive mountains, the evidence of whose existence is alone and
doubtfully afforded by the _débris_ which form the strata of the gold
and diamond placers. The ancients long ago noticed the deposition of
gold in the beds of rivers; hence the phrase “The gold-breeding sands
of Pactolus.”
It has been a favorite theory with many persons of a philosophic turn
of mind that all organic forms were created upon the earth not by
mere chance or hap-hazard, nor by what have been called by the early
geologists “freaks of nature,” but, on the contrary, with some definite
intent on the part of the Creator, and perhaps for the welfare of
mankind. Some of these far-sighted thinkers have advanced their views
so far as to maintain that even obscure animal and vegetable forms
may have some indirect or distant effect upon the well-being of man.
We all must admit that it is indeed a beautiful hypothesis, even if
it be contested by stern and savage arguments. But if we indulge in
this manner of reasoning, there seems to be hardly a limit in natural
philosophy in which we may not seek for evidence.
Can we not include the subject of our treatise among those things
which are supposed to have some influence upon the moulding of human
character? Certainly its geological age, its origin, the beauties and
wonders of its physical properties, and their application to art and
science as well as to the wants of society, furnish evidence to sustain
an inference.
But how can a cold, inanimate object like a gem influence the condition
or expansion of the human intellect? the rigid materialist may say. The
gems, he will maintain, apply only to the superficial wants of man, and
directly tend to degrade rather than elevate our natural morals; that
they are articles of commerce, and that commerce debases our natural
instincts.
On the contrary, we may say that the beautiful in nature of whatever
degree is calculated to assist in the development of mental culture;
and without these beautiful lessons and examples constantly spread
out before us, man would always have remained in a state of utter
barbarism. As we look back upon the history of life, how many of the
triumphs of human architecture may be traced to the suggestions arising
from the observance of the varied forms of nature! Nearly all of the
beauties of the Gothic or Grecian styles may be found existing in the
fossil relics of by-gone ages or even in the multiple forms of existing
vegetation. What grand deductions Newton derived from his studies of
the glories of the opal and the iridescent gleams of the soap-bubble!
Let us follow our theme a little longer. In reviewing the fragmentary
remains of the early periods of the earth’s history, the observer
will admit that there has been a marked progress in even vegetable
life as well as in the animal. For in the primitive ages we find the
non-flowering plants were more numerous than the flowering species.
Therefore, in contemplating the precedence of succession of animal
and vegetable life, the thought naturally occurs to us that perhaps
the most delicate and beautiful of all our flowers elate from recent
geological periods.
We may also apply this hypothesis to the gems, and perhaps maintain
that they too have arrived at perfection by progressive stages. The
corundum, for instance, in the primitive rocks is never so pure and
perfect as the nodules and crystals found in the true gem strata of
recent formations. The emerald of the limestone is also incomparably
above the beryls of the granites. The spinels, the chrysoberyls, the
zircons, and the topazes of the gem beds are generally far superior
to those found in the old crystalline rocks. There are, however, some
plain exceptions to this plausible theory; and the finest of the
tourmalines are found in cavities in granite ledges that appear to be
of an early age.
We are also sometimes inclined to think that color in the early ages
of terrestrial life was wanting in the rich hues which now deck
animate nature. For of all the relics of the old geologic forms that
are preserved to us their colors are either greatly faded or were at
first faintly painted. Even in the tertiary division the hues are
not beautiful. The shells, however, exhibit a trace of the pearly
hue of the nacre, which may once have shone as brightly as in the
modern mollusca. Some of the fossil fishes display a gleam of the
silver tints that now glisten on the sides of the living species.
Fossil corals preserved in the marble, however, have retained the
beauty of form but lost all delicacy of hue, if they ever possessed
any. Still, absence of bright and glowing colors of the animals in
a fossil state is by no means conclusive evidence that nature was
then devoid of external decoration. For we may see on every side
how the beautiful hues of animal and vegetable life may fade and
disappear altogether on the suspension of vital activity; and also
how the process of solidification and petrifaction may modify or even
obliterate all traces of organic color. It is, however, a fact that the
richest-colored gems and minerals are found near the surface of the
earth, as though they required the direct influence of the solar rays,
like the finest varieties of colored coral and the gorgeous flowers of
vegetation.
In reflecting upon these phenomena, and in seeking for the causes that
led to the creation of the diamond, and sifting down the evidence
that science has patiently brought to light, we are naturally led to
philosophic musings. It is a singular reflection that much of our
commercial greatness is derived from luxuriant vegetations of early
ages of the earth’s history. How much pleasure, how many of the
comforts of civilization and even the necessities of life, do we owe
to the extinct fauna of by-gone ages! Even invalid man, seeking to
restore the exhausted fountains of his shattered nature in the waters
of some of the sulphur springs, quaffs the life-restoring principles
from the mineral and animal _débris_ of the lower ocean of the old
red sandstone. Here, then, is a happy adaptation of the vague and
empty theory of transmigration of the ancients,--the metempsychosis of
Empedocles. Certain elements imprisoned in the earth for ages return
again at last to reanimate exhausted man and improve his social life.
The same agency in recent times, and by natural though mysterious laws,
has produced from similar materials the gem, which seems to be quite as
necessary for the superficial wants of mankind as gold or silver.
In studying the earth’s history and examining the successive phases
of its development, we are insensibly led to the idea that all these
stages, seemingly progressive, never retrograde, were for a definite
purpose, if not for the exclusive benefit of mankind. For it is only
just before the introduction of man that some of the highest orders
of vegetation, such as the _Rosaceæ_, appear on the earth. There is
certainly a marked intent in the appearance of the pear, the apple,
plum, cherry, peach, and other fruits, with the true grasses, late in
the tertiary period.
We may also trace this suggestive progression in the development
of even insect life. In the Silurian age the hum of the insect was
unheard; and it was not until the oölitic period that this form of
animal life appeared. A fossil gem--the amber--reveals the time of the
birth of the insect dearest to man; and it was not until the eocene
change that the earth heard for the first time
“The soft murmur of the vagrant bee.”
May we not also place in the same category of possible intents the late
deposition of the diamond? It is not so very strange, after all, when
we come to consider the vast field that lies within the range of the
argument.