I,ENK0SE] PHOSPHORITES OF SPAIN. 55 
Penuelas), and cuts obliquely through the country slate, which has a 
strike of north 159 to 45o east, and a dip of 70° southwest. The vein 
has been worked principally where it crosses hills, and especially near 
the chapel of Kuestra Senora del Oonsuelo. It varies from ten to 
twenty feet in width and contains streaks of quartz and horses of coun- 
try rock. The walls of the slate show signs of considerable decomposi- 
tion and disintegration. The vein thins out at each end, and also grows 
narrow at a depth ; though, as the excavation is only about forty feet 
deep, the bottom has not yet been reached. 1 
The second vein, Jungal, is at the entrance of the town of Logrosan, 
on the road to Truxillo. It has a mean width of 32 inches and a length 
of one thousand to twelve hundred feet. In most respects it resembles 
the Costenaza vein, but is on a much smaller scale. 
The Castillon vein runs under the town for a considerable distance 
and varies in width from five to six and three-fourths feet. It presents a 
mass of phosphorite of great purity. 
The Angustias lead is on the side of the hill Nuestra Senora del Con- 
suelo and runs towards Mt. Boyales. It is not so valuable as some 
of the other leads, because of being much cut up by quartz veins and 
horses of country rock. 
The Terrenos Colorados vein is 330 feet long and averages six and 
two-thirds feet wide. It is parallel to the Cambre Bojera lead, which is 
about the same size. 
The general direction of all these veins is northwest and southeast, 
with a dip of 60° to 90°. 
The Logrosan phosphate has a subcrystalline structure; some speci- 
mens are fibrous and radiating and often resemble feathers. It is soft 
and chalky to the touch, easily broken, but difficult to grind into a fine 
powder. An examination under the microscope exhibits conchoidal 
figures interrupted with spherical grains, devoid of color and opaque 
(Shepard). It is infusible before the blowpipe ; but, on being subjected 
to long-continued heat, a luminous disk, perceptible in the dark, makes 
its appearance at the point of contact of the mineral and flame, and a 
green phosphorescence appears when it is heated for a short time. It is 
readily soluble in hydrochloric, nitric, or sulphuric acid. 
The highest-grade material is rosy white or yellowish white in color, 
soft, concentric, often brilliantly radiated, with a mamillary or con. 
choidal surface. Red spots from iron and beautiful dendrites of man- 
ganese are not infrequent. The poorer qualities are milky white, vitre- 
ous, hard, and, though free from limestone, contain considerable silica. 
The shipment of phosphate from Logrosan involves great trouble and 
expense, The mineral is drawn by ox or mule teams to the nearest rail- 
road, a distance of 30 miles, and is shipped at Villanueva de la Serena. 
This carriage costs about 20 cents per cwt., and the carts make two 
1 Dr. C. U. Shepard, jr., MS. 
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