chloritle
mineral judged to be clinochlore. Numerous tests and experiments are
described looking toward exact determination of the mingled components,
tliougb the precise distinction of them is very difficult. Professor
Clarke says : " The rock is unusual in character; and if the sample
examined is fairly characteristic of the entire deposit, the latter
should be carefully studied in reference to its origin and its
geological relations."
AMBER. TEXAS.
A
yellow, resin-like amber is common in the Cretaceous coals at Eagle
Pass and on Terlingua Creek, as is reported by Prof. J. A. Udden. The
largest pieces are of the size of a grain of corn, and small pieces can
always be easily found.
SANTO DOMINGO.
Mr.
Clarence C. Sample, in an account of the occurrence and production of
amber in Santo Domingo." states that the locality is identical with
that described by Mr. C. W. Kempton in the report of this Bureau for
1903b but it would appear that much progress has been made
in the past two years in the matter of production. The hill on the
upper I.icey River, the locality of occurrence, is one of the foothills
of the Monte Cristi Range, which flanks the north coast eastward to
Samana. and forms the northern limit
of the Vega Real of Columbus, the great central valley plain. The rocks
of the Monte Cristi Range are chiefly sandstones and shales, with some
conglomerate, and are rather soft and much eroded. Amber is found in
them at several points, but the principal district is that of Tamboril.
in a region comprising some 50 square kilometers, a few miles north of
Santiago.
Many
of the beds of shale and sandstone contain carbonaceous matter and some
carry lignite, and it is in these that the amber is found, but
unfortunately no fossils have been obtained to fix the exact age. Mr.
Sample states that the quantity of amber found is only a fraction of a
pound to a cubic yard of rock, so that when the latter is at all hard
there is not enough amber to render working profitable, as any process
of rock crushing would involve breaking up and damaging the amber. It
occurs in pieces varying from small sizes up to several pounds, and in
color from light yellow to deep red. with also a black variety of
little value. The curious fact is noted that the red amber can be
bleached by a few hours' exposure to the sun.
BURMA.
Burmite (Burmese umber).—Amber
has long been known as obtained in Upper I?urma. and the recently
published " Review of the Mineral Production of India from 1808 to
1903," by Dr. T. II. Holland. Director of the Geological Survey of
India.'' gives some interesting facts regarding its occurrence and
production. The quantity and value have varied extremely, but during
the years mentioned the annual output has averaged 51 hundredweights,
valued at £362. The amber is mined principally in the Myitkyina
district, in the Hukong Valley. It occurs in clays, judged to be
Miocene, and has also been recognized in similar strata of that age at
a few other Burman localities. The product is mostly taken to Mandalay.
where it is worked into heads, ear cylinders, and
