68 



VII. Diaphaneity. 



1. Transparent, semi-transparent. 



2. Translucent, sub-translucent. 



3. Opaque. 



VIII. Acid Tests. Use H. Cl. (hydrochloric acid) or dilute H 2 SO 4 

 (sulphuric acid), or both. Use a little of the mineral in a test tube. 



1. Insoluble. 



2. Soluble. With effervescence, with or without heat. Without 

 effervescence, with or without heat. 



IX. Flame Tests. Use a fine splinter of the mineral, or thin edge 

 in the flame of an alcohol lamp or bunsen burner. Note color im- 

 parted to flame. 



1. Fusible melts. 



2. Infusible does not melt. 



3. Decrepitates. Breaks into small pieces with crackling sound. 



4. Intumesces. Swells up without fusion. 



Taken from "Nature Study," by W. S. Jackman. 



