New-York tribune., 1903-03-29
AMERICAN DIAMONDS.
Valuable Pebbles May Be Found in Certain
Gravel Beds in This Country.

The presence Of fresh water pearls in Amert-
can streams is comparatively we'll known fact
The discovery of diamonds in the United States
has not been so widely advertised. largely. no
doubt, because so few jewels of the latter kind
have been found here. South Africa is now the
largest producer in the world. and Brazil ranks
next in present yield. India. Borneo and the
Ural Mountains Of Russia have in the past sup
piled a great many diamonds In nearly every
country which supplies these stones they are
found at a considerable distance from the vein
Of mineral in which they were once deposited
South Africa affords marked exception to the
rule In that part of the world they en-
bedded in pans" or pipes which streaks
Of lava, that have invaded black shaly rock.
The suspicion is now entertained that the In
tense heat of volcanic action may have con-
verted some Of the carbon in the shale into
jewels.
One of the regions in the United States from
which small diamonds have been obtained is
the Piedmont Plateau. at the southeastern base
of the Appalachian chain, between Southern
Virginia and Georgia Nearly or quite a dozen,
reaching D carats in SIZE have been picked
up there, under circumstances that suggest the
proba bity Of having been transported-Tolled
down hill perhaps-many miles from the place
OF their birth. Geological conditions like those
existing at Kimberley have been observed in
Kentucky, but up to date no diamonds nave yet
been discovered in that State. possible eX-
PLANTATION of the failure is the lower proportion
of carbon in the shale.
A somewhat difficult problem is raised by find
Ing diamonds, ranging in size from to
21 carats, and a number Of smaller ones. in the
Great Lake region, under circumstances that in
dicate that they were brought there by the
great ice sheet of the glacial period Most of
the stones were discovered in Wisconsin, but
Michigan and Ohio have each reported one or
two also In every instance the jewels were
hidden in the gravel of kettle moraine.' a
kind Of deposit which geoogietsn recognize as
having been left by a glacier. Since the ice
sheet which carried these stones Hhto the United
States doubtless travelled hundreds of miles,
possibly thousands. it is hard to locate the
centre from which they proceeded, although this
must have been up in British territory some
where. However. Canadian geologists have
land from which the ice sheet flowed existed
west of Hudson Bay. but that the source OF the
ice which invaded the lake region was Labrador
east Of Hudson Bay
The fact Of greatest practical importance is
that other glacial moraines in the United States
may possibly contain Jewels like those already
discovered Ia the lake region There such
deposits IN Southwestern New-York and on
Long Island, for instance. 1t would pay to keep
q sharp lookout where gravelly ridges are being
cut for roads or other purposes in order to In
sure the finding of jewels If any exist there
Diamonds in the rough not exactly round
though they may have blunt corners. They
tend to assume Q crystalline shape, and have
slightly curving. not fat. sides. Some Of the
Wisconsin diamonds had over dozen facets
The form does not closely resemble the cut
Enarksble hardness enables them to scratch all
other substances. Perhaps they may not be
over q sixteenth or an eighth OF an inch In
A1aEascer. But anything family suggestive OF
q eubtcal bit Of material found IN glacial gravel
ought 10 receive critical study. --..