CHAPTER Y. 
Building-stones. — Coal .— Gypsum. — Lead. — Sulphur. 
I.—BUILDING STONE. 
Description of the principal specimens in the collection.—Remarks upon them and their distribution. 
I present under this head a brief description of some of the most interesting roclc-specimens 
in the collection, especially those indicating deposits which can he made use of for purposes of 
construction. These specimens are described according to their numbers in the catalogue, and 
the same descriptions will serve the purposes of the geologist. 
No. 3. Granite from JBueco mountains. —This is a very fine-grained and compact grey, 
sienitic granite, the crystals of hornblende being very small, and appearing as small black 
grains. The feldspar is white and glassy. A fragment of white limestone accompanies these 
specimens. 
No. 5. Limestone from head spring of Delaware creek. —This is a very compact, dark-colored 
rock, and breaks with a conchoidal fracture. The weathered surface is grey. When struck, or 
if cut with a knife, a peculiar bituminous and offensive odor is produced. 
Nos. 6 and 8 are similar to No. 5. 
No. 17. Limestone from foot of Guadalupe mountains. —This is a very compact, firm rock, of a 
greyish-white color, and sub-crystalline grain—saccharoidal. It contains some slight cavities, 
rendering it somewhat porous, hut it may he regarded as a good and elegant building material. 
No. 9. Sandstone from Guadalupe mountains. —This is one of the firmest and hardest sand¬ 
stones in the collection. It has an even grain and pleasing drab color, hut weathers with a 
dark, rusty brown surface. The mass, when held in certain positions, reflects the light as if 
from a cleavage surface of carbonate of lime. It effervesces violently with chlorohydric acid, 
and is, evidently, highly charged with carbonate of lime. 
No. 36. Sandstone from Llano Estacado. —This specimen much resembles No. 9, hut is more 
compact, and probably contains more lime. The brilliant reflections noticed in No. 9 are very 
evident here, and are manifestly due to a partial crystallization of the carbonate of lime. The 
color of this specimen is a rusty brown, and darker than No. 9. 
No. 27. Sandstone from east side of the Pecos. —This is a firm, compact specimen, of a uniform 
grain, and sufficiently tough for building purposes. It does not, however, look very durable. 
No. 30. Sandstone from Llano Estacado. —This specimen is coarse-grained and quite friable. 
It contains a notable quantity of carbonate of lime, and probably is not very durable if exposed 
to the weather. It resembles the Tertiary sandstones of the Bernardino Sierra, California. 
Nos. 19, 20, 23, 24. Sandstones. —These specimens have a general resemblance. No. 23 has a 
reddish color, due to the presence of oxide of iron, hut in other respects it much resembles No. 30, 
and, like it, may he crumbled away by the fingers on the thin edges. No. 19, from near the 
river, is peculiar. The little grains of sand are cemented by a thin white crust, which is carbon¬ 
ate of lime; and when the grains are crumbled out, small cavities are left in the calcareous mass. 
No. 20 is similar, hut contains same large pebbles. No. 24 has the same general characters, hut 
is much coarser. All these specimens have a modern look, and resemble the Tertiary sandstones 
along the margin of the Colorado desert, where some of the upper beds are highly charged with 
carbonate of lime in the form of travertin, or calcareous tufa. 
