New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1899-05-21
THE ORIGIN OF DIAMONDS
VOLCANIC ACTION BOTH MADE AND
PLACED THEM.

PLACED THEM.
RErENT THEoRIEs-THE SURROUNDING OF THE
FAMOUS SOUTH AFRICAN MINEs-THE SIG
NIFIcANCE OF MoIssANs EXPERIMENTS
gems IN METEoRs.
From The Edinburgh Review
Tho great Karoo formation spreads ike a
mantle over two hun 1red thousand square nie'
OF South Afrca-east and west from the opr stt
kop to the Red Heights above MlddleDuis, ho, -
and south from the Black Mountains 10 the
Vaal River Its component beds were depoSlteu
at the bottom OF inland sea curing INC
Triassic age when the Labyrinthodon, or mon.
ster toad-lizard, led the van or creation, ou s
their succession alternated with upWelIngs OF
molten basalt, which spread into lever sneets
intercaated between the carbonaceous Shaes
representing the lacustrine ooZe ana the lacuS-
trine vegetation of an all but endless epoch
They appear to have proceeded in comparative
tranquility those cOpious lava inundatlons
Vehement volcanic action was delayed until the
complete stratification of the karoo had peeh
ACCOMPLISHED Provoked, doubtless by water
infItrations to the smoudering volcanic focl De
meath. tremendous explosions then took place
enormous volumes OF gas were eVolVed, anu
irresstbly expanding, perforated the superin-
cumbent rocks with ample channels of escape
These did not remain empty. BY spasmodic Ell
forts most likely, not all at once nor all to-
gether they were replenished from below. Oh
genuine igneous eruptions no traces remain: the
work was done by mud -rushes transporting up
ward miscellaneous Subterranean debris, largely
intermixed with floating reefs"-fragments
that is to say. torn from the circumjacent stata
the whole being agglutinated by tufaceous
stuff into a volcanic breccia. This volcanic
breccia is the blue ground" of Kimberley, the
indus of South African diamonds.
THE KIMBERLEY MINES INEXHAUSTIBLE.
Such. apparently, is the history Of these sin
gular repositories. They are not properly
speaking. extinct craters, but rather gigantic
blow-hOles, excavated catastrOphically, reiilled
gradually. The core materials in each pipe
represent several "pours."
This blue" rock-named "Kimberte" by
Professor Carvill Lewis-s really OF dull green
tint due to its mpregnation with iron oxides
which apprOpriating an additional equivalent
of oxygen on exposure to the air. turn yellow,
and give to the upper sections and SuDaerial
fields their well-known ochreous aspect. Es-
sentially the same material is, however, now ex-
caVated at depth of close upon two thousand
feet, was struck by the first prospector 5 pick
axe thirty years ago The mines, unless all the
Indications at hand prove deceptive are bot
tomless. Their precious contents. instead Of
''petering out" with descent. grow more abun-
dant. They supplied, perhaps, by direct
communication with reservoirs so profoundly
subtorranean as to be accessible only to those
personally conducted by Virgil or Jules Verne.
1t appears certain moreover that each pipe was
fed from an independent source. Their products
separately recognizable. A trained eye can
distinguish De Beers from Kaffeefontein dia-
monds; those dug within the range Of rifle
bullet at Bullfontein and Dutoitspan show
discernible difference of color; the perfect
hedrons of Newlands resemble neither the irreg
ular white stones from WesseltOn nor the cross
grained frosted stones from Leicester; while
the Jagersfontein gems remind connosseurs by
their steely glitter of the old Indian "blues"-the
''Orof." the Regent. the "SaLcy"-and fetch
proportionately high prices.
MAKING CARBON VAPORIZE
Our readers do not need to be told that dia-
monds are composed Of pure carbon Hence,
alone among gems. spurious or true. they
perfectly transparent to the R0ntgen rays Sill
lea, the usual substratum Of jewels, glass paste,
crystal are all comparatively Opaque. An easy
and infallible test for genuine diamonds has thus
been Unexpectedly provided by the Wurzburg
professors memorable discovery
Carbon is an eminently intractable substance.
At ordinary temperatures no solvent can be
found for it. At no temperature, unless by
tcaordnary cOmpulsion will it consent to melt.
In the electric arc it passes directly into vapor.
skipping the intermediate state.
The key to the enigma of diamond production
should accordingly be found in the liquefaction
or carbon. The circumstances under which il
is accomplished can hardly be other than dent-
cal with those attending the development of the
precious stones Now, it Is possible to deter
mine approximately. by calculations based on
the analogy OF other substances the nature of
those circumstances This has been done by
Professor DeWar He finds the boiling point or
carbon to be 1914 centigrade degrees above the
absolute zero equivalent to 5000 degrees on
the ordinary scale; the critical point" is in the
neighborhood of $500 degrees (absolute) and
the corresponding critical pressure" scarcely
IL at all. falls short Of fifteen tons to the square
inch
CARBON DISSOLVED IN IRON
That fused iron dissoves carbon is no recent
discovery, but the affinity. illustrated in the
Bessemer process. has been widely developed
and investigated by NJ. Moissan. At the tenn
perature Of the electric furnace he finds this
ntractable substance to be freely
soluble In aluminium. chromium manganese.