60 HANS EEUSCH. GrEOL. IAGTT. EEA TEONDHJ. STIFT. [No. 7. 1890.] 



The reason why it has not been more used are various: the 

 difficulty of obtaining large blocks of pure stone, the difficulty 

 of polishing the stone and the brittle nature of the same. Un- 

 der the microscope (fig. p. 46) the red constituent is seen to be 

 besides thulite also piemontite or red monosymetric epidotp, lastly 

 also an admixture of some common epidote. The thulite -stone is 

 not sharply defined from the surrounding rock but merges into it. 

 It must be supposed to have been formed out of the granitic 

 rock chiefly by the felspar of the latter being replaced by 

 epidote minerals while the mica has vanished. At Leksviken 

 church at some distance from the occurrence of thulite stone, 

 black manganese ores have been found, but they have not been 

 more closely examined as yet. The quarry of thiute-stone is 

 depicted p. 48. 



The last diagram shows a rock about 5 m high of gneiss 

 of middle-sized grain. Along a plate between x and x, about 

 1 m. broad, a faulting has tåken place; in this plate the gneiss 

 has got a plane parallel structure differing from that of the 

 surroundings ; it is rich iu chlorite, to the miked eye remark- 

 ably fine-grained, and under the microscope showing a cataclastic 

 structure. 



Trykt den 3die februar 1891. 



