PHYSIOGRAPHY. 21 



Anglesite. Anhydrite. 



Lustre adamantine, inclining to vitreous and resinous. 

 Color yellowish, greyish, or greenish white, also yellow- 

 ish, smoke and ash-grey. Sometimes faintly tinged green 

 or blue. Streak white. Transparent. . . translucent. 



Brittle. Hardness = 2-5 ... 3-0. Sp. gr. = 6-298. 



Compound Varieties. Massive : composition lamellar, 

 also granular, of various sizes of individuals, often strongly 

 connected. Faces of composition rough. 



1 . It decrepitates in the flame of a candle,, and frequently assumes a 

 slight reddish tinge on the surface. Reduced to powder it melts easily 

 before the blow-pipe into a white slag, which is reduced to metallic 

 lead by the addition of soda. 



2. Analysis. 

 By STROMEYER. 



Oxide of lead . . . 72-47 



Sulphuric acid . . . 26-09 



Water . . . 0-12 



Hydrous oxide of iron . . . 0-09 

 Oxide of manganese . . . 0-06 

 Silica . . . 0-51 



3. It is found in lead and copper veins, traversing clay-slate and grey- 

 wacke slate, along with various ores of lead and copper. 



4. It is found at the Lead hills and Wanlockhead in Scotland, Pary's 

 mine in Anglesea, Mellanoweth in Cornwall ; also at Clausthal and Zel- 

 lerfeld in the Hartz, near Freiberg in Baden, at Siegen in Prussia, in 

 Spain, and Siberia. 



It occurs along with Galena in the lead mines of Missouri : also in the 

 lead mine of Southampton, (Mass.) 



ANHYDRITE. Prismatic Gypsu m-H a 1 o i d e. 



MOHS. 

 Primary form. Right rectangular Prism. 



