South Bend news-times. (South Bend, Ind.) 1913-1938, 1918-07-23
The Romance of Iceland Crystals

I
The very interesting statement has
just come from Dr. c. L. Parsons of
the bureau of mines. Washington.
that large deposits Of pure calcite
have been found in Montana, and
that the crystals occurring there
appear 10 be the nearest approach
TO Iceland spar yet uncovered in any
part of the world. This is great
news for many workers i'm science.
for large. pure transparent crystals
of calcite are rarer than frst-water
diamonds, besides being incompar-
able more useful
Calcite is a native carbonate OF
calcium. and calcium is the element
out of which the great limestone
hills. the vast chalk deposits and
the beautiful marbles of the earth
/ have been formed. Fossil shells
and corals. that carry the geological
history of life back hundreds of
millions of years. were built up from
calcium carbonate.
Calcite crystals are found in
many parts Of the earth, but, hither-
to. there has been only one place
where they were found large enough
land clear enough TO serve as instru-
ments for scientific investigation,
l and that place is near the middle OF
/ the east coast Of Iceland. close by
/ the Reidar ford i'm cavern about
/ 10 feet high. - wide, and not much
more than twice as long as broad,
/ which. when discovered some three
centuries ago. was stuffed with mag
nifcent crystals. some OF which
were three feet I'm diameter.
And from that time 10 this that
little cavern ia the basaltic mass of
the volcanic rock-hoWer of the
northern ocean. crowned with the
white peaks OF Hekia, has remain
ed virtually the sole source known
To man of "optically perfect cal
cite CRYSTALS. although of late it has
been failing i'm its supply of first
4 class material
| anu tA AciANAhAAA II oAAA tAeAe "a
4 WAYS been one OF the most album
dant substances ON the earth. So
excessively rare are some of nature 5
most exquisite performances! 81
IInfrequently does she repeat a mas
terstroke!
But what. then. are the powers o.
properties. that give so great dis
tinction 20 Iceland spar. These
icrvstaIs produce the phenomenon OF
double retracton A ray of light
sent through one of them is split
into two pencils one of which is
bent out of its original course more
than the other 50 that objects seen
through the crystal appear double
That is "A brief statement OF the
property of Iceland spar which first
made il famous.
More than that 1t was the find
ing of the strange crystal cave ia
Iceland that leo 10 the discovery OF
doubIe tef5action itself for it was
not until Erasmus Bartholinus OF
/ l'opel.haE gen. n 1869. or Whereabouts
while examining one of the crystals
that had come into his possession
saw objects doubled by il, that
science first learned OF the existence
Of such a phenomenon.
Barthounus. although a student
of science. could not explain the eff
feet that the crystal had on light
and looked upon il as one of nature
freaks. until Christian Huygens took
Iup the investigation and worked out
the theory OF double retraction And
this same wonderful kind Of crystal
also introduced 90 the notice O.
science another surprising phenom
+ enon associated with double re-
fraction. viz polarization of light
While Huygens was experiment
Ing with the drst OF the two newly
discovered phenomena ne became
aware of the existence Of the sec
oud the Iceland crystal being the
agent ~ revelation in both cases
, With the exception Of the lode