618 MINERALOGY 



IV. The coat is white, with a metallic-like luster, and yields a 

 selenium odor, also colors the flame blue. Test p. 587, p. 626. 



V. The coat is yellow when cold, at least near the assay, and 

 with von Kobell's flux shows lead or bismuth. Test p. 579, p. 627. 



VI. It yields sulphur dioxide when the powder is heated in the 

 O. F. on coal, or it yields a strong sulphur reaction on silver after 

 fusion with soda ; p. 629. 



VII. Reduced with soda and borax and a little powdered coal, 

 it yields a malleable metal ; p. 631. 



VIII. The powdered mineral when dissolved in the borax 

 bead shows manganese. Test p. 574. The mineral is infusible; 

 p. 632. 



IX. The mineral when powdered and heated in the R. F. on coal 

 becomes magnetic; p. 632. 



X. Minerals not included in the preceding groups ; p. 634. 



NON-METALLIC MINERALS OR MINERALS WITHOUT METALLIC OR 

 SUB-METALLIC LUSTER 



Minerals included here yield a streak and powder light in color, 

 and will usually transmit light, at least on the thin edges. 



I. The mineral has a decided taste, soluble, or soluble to a large 

 extent in water. Hardness below 3. No minerals containing 

 copper or arsenic will be found in this section; p. 635. 



II. Easily and quickly volatile (if pure) when heated on coal. 

 If the mineral decrepitates, it should be heated in the closed tube, 

 when it volatilizes and yields a sublimate ; p. 640. 



III. Roasted, and then reduced with soda, borax, and a little 

 coal dust in R. F. on coal, yields a malleable button. 



A. The button is copper or contains copper ; p. 641. 



B. The button is silver ; p. 645. 



C. The button is tin ; p. 646. 



D. The button is lead, or the mineral fused with von 



Kobell's flux shows lead ; p. 646. 



IV., Fused with soda and borax in the R. F. on coal, it yields 

 an oxide coat. The arsenic coat is included in Section V ; p. 649. 



V. In R. F. on coal yields an arsenical odor, or the powdered 

 mineral heated with a few fragments of coal in a closed tube yields 

 an arsenic mirror. Test p. 585, p. 651. 



