PHYSIOGRAPHY. 123 



Pseudo-Malachite Psilomelane. 



Brittle. Hardness = 4-5 ... 5-0. Sp. gr. = 4-205, a 

 crystallized variety, from Rheinbreitbach near Bonn. 



Compound Varieties. Reniform, rather imperfect : 

 composition imperfectly columnar ; surface drusy, and often 

 of a darker color. Massive : composition as above. 



1. Before the blow-pipe, it melts with ease, and is converted into a 

 small, vesicular, metalloidal globule. It is soluble without effervescence, 

 in nitric acid, particularly if heated. 



2. Analysis. 



By KLAPROTH. By LUNTV. 



Oxide of copper . . 68-13 . . . . 62-847 

 Phosphoric acid . . 30-95 .... 21-687 

 Water . . 0-00 .... 15-454 



3. It is found in veins traversing grey wacke slate, and is accompanied 

 by several varieties of Quartz and ores of copper, in the Virneberg near 

 Rheinbreitbach on the Rhine. 



PSILOMELANE. Uncleavable Manganese- 

 Ore. MOHS. 



Regular forms and cleavage unknown. Fracture not 

 observable. 



Lustre imperfectly metallic. Color bluish-black and 

 greyish black, passing into dark steel-grey. Streak brown- 

 ish black, shining. Opake. 



Brittle. Hardness = 5-0 ... 6-0. Sp. gr. = 4'145, a 

 botryoidal variety. 



Compound Varieties. Reniform, botryoidal, fruticose: 

 composition columnar, impalpable; fracture flat conchoidal, 

 even ; in a second curved composition it is curved lamellar, 

 the faces of composition being smooth, rough or granulated. 

 Massive : composition granular, impalpable, strongly con- 

 nected ; fracture flat conchoidal, even. 



