TO DETECT MINERALS BY THEIR COLOUR, ETC. 33 



Also mercury, palladium, osmium, iridium, lead, antimony, tellu- 

 rium, &3. 



Graphite has a dark steel grey metallic lustre and black metallic 

 streak. 



MINERALS OF METALLIC LUSTRE. 



Certain micaceous iron minerals, which giro a red streak, are some- 

 what metallic-like in appearance. 



* The streak has a metallic lustre. 



