70 DOMAIN I. SIDEROUS. 



Bricia of fragments of basal tin, joined by a 

 cement of quartz, intermixed with particles of 

 basal tin. Uncertain. 



STRUCTURE II. COLUMNAR. 



pasaitin of Aspect 1. Uniform. Basaltin, from Stolpen. 



Stolpen. , 



in Saxony. Remarkable as having attracted the 

 attention of Agricola, and other naturalists since 

 the sixteenth century. The little town of Stolpen 

 is built upon the side pf a basaltic hill, a few 

 miles to the east of Dresden. The lower part of 

 the hill consists of a granite, of white felspar, 

 grey quartz, and black mica, upon which the ba- 

 salt reposes, presenting the most beautiful and 

 regular columns observable in Germany*. They 

 have commonly six sides; but some have four, 

 five, seven, or eight; yet their length does not 

 seem to exceed fifteen or sixteen feet. The co- 

 lumns are vertical ; but on the south-east there is 

 a rock of stratified basalt, of that kind which ap- 

 pears in thin plates or tables. The basaltin of 

 Stolpen is black with a bluish cast, the grain being 

 impalpable, the fracture conchoidal, and the frag- 

 ments sharp. Its hardness, like that of siderite 

 and basalt, equals that of iron the hardest metal, 

 jbeing more than 800 of Quist's gradation. This 



* Daub, sur les basaltes, 42. 



