OBDEtt vi. PRISMATIC FELD-SPAll. 263 



Among the most remarkable places of occurrence of some 

 of the species of Feld- spars, certain meteoric stones deserve 

 to be mentioned, as those which fell in 1807 at Stannern 

 in Moravia, and those of 1821, at Aubenas (HAUY. Traite', 

 2de Ed. T. III. p. 537.) in France. In general, these spe- 

 cies appear to have a considerable share in the composition 

 of the meteoric masses. 



4. The finest crystals of Adularia, both prismatic Feld- 

 spar and Albite, are found in the highest districts of St 

 Gothard and the Alps of Savoy, several varieties occur also 

 in Salzburg, the Tyrol, Bavaria, Dauphiny, the isle of Arran, 

 in Cornwall and Wales, &c. The largest crystals of Albite 

 hitherto known are from Kerabinsk in Siberia. Also of 

 the prismatic Feld-spar large crystals have been found in 

 that country ; they are generally penetrated by rhombo- 

 hedral Quartz, sometimes of considerable transparency. The 

 twin-crystals from Carlsbad in Bohemia (Fig. 80. and 81.) are 

 well known, and belong to prismatic Feld-spar. Amazone- 

 stone, a verdigris-green variety of prismatic Feld-spar, often 

 associated with small white crystals of Albite, occurs near 

 Fort Troitzk in the Uralian mountains. Labradorite was 

 first brought from the coast of Labradore ; it occurs also 

 in Ingria, in large but not well defined crystals in Green- 

 land, and as a constituent of several rocks in various places of 

 the Hartz, Saxony, near Florence, &c. It has been observ- 

 ed above, that what has been called Labradorite from Nor- 

 way, in fact belongs to the species of prismatic Feld-spar; 

 it occurs in the zircon-syenite of Friedrichsvarn. Com- 

 pact felspar, forming the body of clinkstone-porphyry, is 

 found in the Bohemian Mittelgebirge, in the Western Isles 

 of Scotland, at Sahla in Sweden, in the Hartz, &c. Va- 

 riolite has been noticed from Piedmont and Corsica. The 

 finest varieties of Porcelain earth are those from China, 

 where it is called Kaolin, from Saxony, from Passau, and 

 from Limoges in France. The repository of porcelain- 

 earth near Carlsbad in Bohemia, is of secondary formation, as 

 it is there accompanied by basalt, clay, sandstone and coaL 

 5. Several varieties of the different species included in 



