130 



THE GUIDE T< ) MATURE 



methods employed. It is certainly 



true that all of our most prized min- 

 erals from those mines are of the most 

 fragile character, and would he very 

 susceptible to damage of this kind. 

 Among thoe are thiorite. calcite, ga- 

 lena, sphalerite, siderite, hematite and 

 pyrite. 



IX. Calcite. Guanajuato, Mex. 



This is a handsome specimen, show- 

 ing a beautiful snowy wdiite crystal, 

 three inches long. The crystal itself 

 is pure white within, and has a thin, 

 transparent coating of calcite com- 

 pletely covering" it. It is the common 

 combination of scalenohedron and 

 rhombohedron. It rests against a 

 greenish background, covered with 

 little calcite crystals. The crystals on 

 the front of the specimen are clear 



quartz, of a very fine, deep amethyst 

 color. This makes a combination very 

 pleasing to the eye. 



The specimens from Guanajuato are 

 famous for their beauty and perfection, 

 the combinations of snowy calcite with 

 amethyst quartz and apophyllite can 

 hardly be outdone by any other local- 

 ity in the world. 



X. Calcite, (Iuanajuato, Mex. 



These crystals seem to most re- 

 semble hexagonal plates, they are pecu- 

 liar, however, in that the rim and 

 centre of each one is raised, leaving a. 

 circular trench between. The edges 

 of the crystals are highly modified, 

 and their color is a beautiful snowy 

 white. All considered, this specimen 

 is a very good representative of the 

 best that Guanajuato has given us. 



IX— CALCITE ON AMETHYST FROM MEXICO. 



