192 EARTHS. AGGREGATE. 6i. Porphyrius. ^ 



H. PFith a hafe of pitch, 



plceui. Compofed of pitch, fcldfpar, and quartz- 



Hoffmann Berg. "Journ, I 788. 2, ^.491. 



Pitchllone Porphyry. Thomjon. \. p XT^'i^. Kirivan. 1.^,351, 

 Found near Mifena in Saxony^ forming entire mountains alter- 

 nating with r.iountains of porphyry and clay, in horizontal 

 Itrjta : colour black, green, brown, or red, 



1. I'Vith a hafe of chert or horn/ione. 



i^istosus. Confirting of hornftone and feldfpar, of a llaty texture. 



Hornfchiefer. Charpfnt. geogr. chuf p. 21. 24, 25. 28. 



Porphyrfchiefer. M^'emer clajjjf, p, m. fe6i. 1 1 . 



Hornporphyr. Noje orogr, i. p. j. 



Horn porphyry. Kir-ivan mineral, i, ^. 352. 



Found common in Bohemia^ Luface^ and in the bifhopric of 

 Fulda^ rarely containing ores of metal : colour generally grey, 

 rarely black, and often marked with arborefcent ramifications; 

 in Italy it approaches to a bafalt, and melts in the fire to a 

 yellovviili glafs, but not fo eafily as bafalt: the chert and 

 feldfpar are mixed in various proportions, to which is fome- 

 times added hornblend, rarely mica, garnets or fpar, very 

 rarely veins of marble. 



nathus. Confifting of hornftone and feldfpar, of a fplintery tex- 

 ture. 

 Karsten Lsfke mineral, z. p. Z^* 

 Hornftone porphyry. Thofnf. chem. 4. p, 133. Kirvcan i. 35 !• 



1 . Of a texture approaching to conchoidal. 

 Hornileinporphyr. Nofe orogr. i,p.\6. 



2. The feldfpar very intimately and finely intermixed. 

 Hornquartz porphyr. Nofe orogr. i. /, 16. 

 Hornartiger Trapp. Lafius Beob.Harz.. p. 17. 112, &c. 



3. With particles of jafper added to the chert and feldfpar^ 

 Hornartiger Porphyr, Nofe orogr. i. p. 16. 



4. With quartz added to the chert and feldfpar, 

 Karflen Lefke mineral. 2. p. 27, 



5. With hornblend added to the chert and feldfpar, 

 Karjien Lefke mineral. 2. p. zj. 



Found in various proportions of conftituent parts and colours, in 

 the mountains of lower //«/y, Hungary^ Bohemia^ Luface^ 

 Saxony^ Carinthia^ the boundaries of the lower Rhine and 

 Denmark^ frequently exhibiting particles of hornblend, mica 

 and iiiorl. 



