1 6? 



TAB. CCCXC1I. 



PLUMBUM sulphureum* 

 Slickensides Galcena. 



Div. 2. Imitative. 

 Syn-. Spicular compact Lead Glance. Jameson 2. 355. 

 Compact Galsena. Kirw. 2. 213. 

 Slickensides. Bab. J 70. 

 Plomb sulfure compacte. Haiiy 3. 461. 



i. his variety of Galaena, rare in any country but England^ 

 is found chiefly at Castleton in Derbyshire, and 1 have some 

 specimens marked Ecton Mine, which is partly in Stafford- 

 shire. It appears to be the common Galaena, but, by a 

 certain slip of two faces as it were of a separated mass of 

 rock, is pressed into a finely granulated compact appearance, 

 quite losing the regular cubic fracture, otherwise usual to 

 Galaena, and which so essentially distinguishes it from 

 most other substances. Sometimes this is rather massy in, 

 the interior part of the specimen, near or quite adjacent to 

 the polished face, caused probably by the broken ends of 

 strata slipping and pressing against each other. It may be 

 on the face of mixed rocks, on Fluor, Quartz, and Sulphate 

 of Earytes. It is said to be dangerous sport to the miners 

 when they meet with it unexpectedly, as it is easily detached 

 with a sudden explosion, and is thrown with such consider- 

 able force that it has even been fatal to those that are within 

 its range of action ; but when, as by experience, they have 



