New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1903-08-30
PEARLS AND THE PEARL FISHING INDUSTRY
GROUTH OF THE FRESHVATER FISHERIES OUT
BREAKS OF EXCITEMENT

For some years pearls have been steadily in
creasing in value and for the best varieties out
rank the diamond in value. This increased value
is accounted for by the fact that the supply Is FAR
from equal TO the demand. while the demand has
been largely caused by the dictate of fashion
Formerly marine pearls furnished four-fifths Of
the available supply. but these fisheries have gradu
ally fallen off until now they produce only about
three-hfths of the yearly yield. the rest being
made up of freshwater pearls. considerable part
of which are found here
In this country freshwater pearls are generally
found in bivalve shells of the family Unionide
also known the Naiades- These mussels are
most abundant in swift and clear water, where
the bottom is sandy gravely and the country
rock caIcareous. The pearls found are few, and
those of market value represent the destruction Of
thousands of mussels for every one obtained. The
soft internal parts of these mollusks are covered
by a thin, delicate membrane. called the mantle
from the surface and particularly from the outer
edges of which material is excreted to form
the inner layers of the she'll Whenever by acct
dental injury disease or intrusion OF foreign sub
stances local irritation is set up IN these tissues
the effect is to produce increased secretion Of
the nacreous at this point. resulting in the
formation of pearls or pearly concretions.
Pearls are of several distinct kinds differing in
shape and perhaps IN origin Free pearls those
that are found loose and separate between the
folds or layers of the mantle and gills or between
the latter and the body of the muLusk, comprise
most of the true spherical pearls. as also many
that are ovate. pear shaped and irregular. Then
there are the pearls found between the mantle and
the valves Of the she'll these If free at all, are apt
to be hemispherical or in any hattened on the
side toward the shell, while often they are at
tacbed more or less to the valve by deposit OF the
pearIy secretion In the region OF the hinge these
become extremely irregular in shape and OFTEN
greatly elongated, forming third kind known as
hinge pearls, baroQues. etc.
The freshwater pearls differ from the marine
pearls in their greater variety of tints and IN the
partial transparency Of their nacre. In color the
freshwater pearls present an extended series OF
shades from dead opaque white, having httie
value through various unts OF PINK yeAoW anu
salmon or a faint purple. passing to bright red.
so closely resembling drop Of molten copper as
almost to deceive the eye Some are very hght
green and brown, others rose color. and st others
are male steel blue. russet and purplsh Drown IN
addition to their color and ustre, they beautl-
fully iridescent and at times the white and pink
nearls are more lustrous than the best Orien-
tai pearls.
MANY oddly shaped pearls are found. Elongated
Asblile forms found near the hinge of the shell
and called hinge baroque pearls are abundant
Others. with a slight addition OF gold and enamel,
may be made represent human ana animal
heads bat and bird wings and similar OBJECTS A
nearl was found in this country that strikngly
resembled the bust of Michael Angelo. In few
instances small fishes and crabs which entered the
shell have been imprisoned and covered eventually
with nacre. thus making pearls OF thenn' at the
same time retaining the animals shape
Frequently pearls have Opaque appearance
and seem TO be worthless. but on the removal or
their outer layer are found to be clear and ir-
descent The outer layer may be removed by
dipping them in a weak solution of acid, which dis
solves the OPAQUE coating. or it may be peeled with
a knife ike an onion. although this is hazardous.
as sometimes the pearl is not Of the same ma
teraI throughout and cannot be restored after be-
ing peeled
Examinations which have been made of some OF
the mounds OF the Mississippi Valley. particularly
in the Miami and Scioto valleys in Ohio. have re-
veaIed the fact that the long forgotten race
that erected these remarkable structures gathered