se 
Class IV. 
Order VIII 
Properties. 
Naleles. 
Properties 
ORES OF LEAD. 
times cuneiform, and sometimes their solid angles are 
wanting *. 
Its colour is commonly bluish grey like lead. Streak 
bluish grey and metallic. Lustre metallic. Sometimes 
stains the fingers. Texture foliated. Fragments cubi 
cal. Hardness 5 to 7; sometimes even 9. Brittle. 
Specific gravity 6.884 to 7.786 †. Effervesces with ni 
tric and muriatic acids. Before the blow-pipe decrepi 
tates, and melts with a sulphureous smell; part sinks 
into the charcoal. 
It is composed of from .45 to. 83 lead, and from .086 
to .16 of sulphur. It generally contains some silver, 
and sometimes also antimony and zinc. 
Variety 1. Common galena.—This variety corresponds 
nearly with the above description. Specific gravity 
7.051 to 7.786. Sometimes stains the fingers. 
Variety 2. Compact galena.—Found only in amor 
phous masses. Texture compact, inclining to foliated. 
Hardness, 6 to 8. Specific gravity 6.886 to 7.444. 
Lustre common. Streak lead grey, brighter, and me 
tallic. Often feels greasy, and stains the fingers. 
Sp. 2. Black lead ore f. 
This ore, which is found in Germany and Brittany, 
and which is supposed to be common galena decayed, 
is sometimes in stalactites of various forms, and some 
times crystallized in six-sided prisms, which are general 
ly truncated and confused. 
Colour black, often with some streaks of red. Streak 
light bluish grey. Internal lustre metallic. Hardness 
5 to 6. Brittle. Specific gravity from 5.744§ to 5. 77. 
Watson. 
* Romé de Lisle, ili. 364. 
Gellert. 
§ Brisson. 
Kirwan, ii. 221.