=~ 
Mar. 1899. THE Ores or CoLtompia—NIcHOLs. 135 
‘¢31, Limestone dike (szc) in the syenitic formation of Remedios,” 
The interesting specimen thus catalogued is unfortunately miss- 
ing from the collections. It is uncertain whether this is merely bad 
English for a calcite vein, or whether it refers to a porphyrite or 
other dike, the material of which is so kaolinized as to resemble 
limestone. 
‘¢32, Quartz and pyrites, ore from the Cogotes mine.”’ 
‘33. Colorado ore with native gold from the Cogotes mine.”’ 
A colorado ore is an oxidized ore, which takes its name from 
the red-brown iron stains which often accompany such ores. 
‘¢34. Quartz and pyrites, ore from the Cogotes mine.”’ 
‘¢35. Quartz, ore from the Cogotes mine.”’ 
‘36. Colorado ore from the Italia mine.” 
*¢37. [E 1050.] Colorado ore from the Italia mine.” 
This is a good example of the ‘‘co/orado”’ or iron-stained ore. 
It is a firm quartz of a pinkish cast, strongly iron-stained along 
the seams, and honeycombed in places where pyrite has been 
dissolved out. It contains many angular fragments of kaolinized 
country rock, similar to that of the other specimens. The small 
pseudomorphs of hematite after pyrite and blende, which usually | 
occur in such ores, are present. 
‘©3238. Veinstuff from the Pujidos mine.” 
‘39, Quartz, ore from the Pujidos mine.” 
*¢30. Pyrites, ore from the Pujidos mine.’ 
‘‘at. Quartz and pyrites, ore from the Pujidos mine.”’ 
‘42, Ore from the Providencia mine.” 
‘43. Ore from the Providencia mine.” 
‘ga. Ore from the Providencia mine.”’ 
‘45. Quartz, ore from the Providencia mine.’’ 
‘*46. Quartz and pyrites, ore from the Providencia mine.” 
‘47,  Porphyritic rock, igtrusion in the Providencia mine.”’ 
“48. [E 1o51.] Quartz, ore from the Providencia mine.” 
This resembles specinien No. 15, except that the galena is in 
very small quantity. 
‘4g. Ore from the Providencia mine.” 
‘50. [E 1052.] Ore from the Providencia mine.”’ 
This clear, white quartz, which is somewhat iron-stained on 
the seams, contains a few small undecomposed pyrite crystals and 
a few casts of larger ones, either filled with limonite pseudomorphs, 
or containing quartz crystals. 
‘51. Ore from the Providencia mine.” 
meee. [1053] Ore from the Sucre mine.”’ 
