NATUBE-STUBY LESSONS. 



163 



(a) The sources and uses of minerals. 

 (d) Their condition, whether soHd, hquid or gas- 

 eous. 



(c) Their form, whether massive or crystalline. 



(d) Their chemical composition. 



(e) Their physical properties : — 

 (1) Related to Light— 



— Intensity- 



I— Lustre — 



—Reflected— 



—Color. 



■ Quality — 



— Streak, i.e., the 

 color of the fine 

 powder. 



— Splendent, as galena. 



— Shining, as calc-spar. 



Glistening, as ice. 



Glimmering, as granu- 

 lated limestone. 



— Dull, as chalk. 



— Metallic, as tin. 



— Adamantine, as diamond. 



Vitreous, as quartz. 



Resinous, as garnet. 

 — Waxy, as opal. 

 — Pearly, as talc. 

 — Silky, as asbestus. 



— Transmitted (diaphaneity)- 



(2) Related to Heat— 



— Transparent. 

 — Semi-transparent, 

 — Translucent. 

 — Opaque. 

 — Conductivity. 

 Dilatation, 



— Fusibility 1, Stibnit«, 



— 2, Natrolite. 

 — 3. Garnet. 

 — 4. Actinolite. 

 5. Orthoclase. 

 — 6. Bronzite. 

 — 7. Quartz. 



