196 Schaller and Hillebrand — Chemical Notes on Lawsonite. 



Measured. 



(j> p 



0° 23' 28° 07' — 14' 

 00 28 07 



Calculated. 

 P 



0° 00' 28° 59' 



The combinations observed on the crystals measured are 

 shown in the following table : 



Cryst. No. c b m d e r s 



1 









m 



d 





r 





2 - 





b 



m 



d 







s 



3 







„ _ 



m 



d 





r 





4 



c 



b 



m 



d 



e 







5 







b 



m 



d 









6 



c 



- - 



on 



d 



e 







The following table is a calculation of the two new forms 

 corresponding to the tables given in Goldschmidt's Winkelta- 

 bellen. 



No. 



Let- 

 ter 



Sym- 

 bol 



Mil- 

 ler 



<P 



P 



fo 



Vo 



c 

 5 



V 



X 



(Prism) 

 (x :y) 



y 



6 



7 



r 

 s 



2 

 3 



221 

 331 



56° 22' 



69° 27' 



75 58 



65° 45' 

 73 17 



55° 54' 

 65 42 



51° 13' 

 53 53 



31° 14' 

 32 30 



2-2204 

 3-3306 



1-4770 

 2-2155 



d = 



tgp 



2 6667 

 4-0001 



Material carefully purified by the Thoulet solution followed 

 by repeated electromagnetic extraction, and having then a 

 specific gravity of 3* 121 at 25°, gave the following results of 

 analysis :* 



* Concerning this purified material, Dr. Eansome reports as follows: "I 

 should say the material is as pure as it is possible to get it. The grains are 

 all lawsonite, but vary in individual purity. Some are perfectly clear. 

 Others have minute inclusions, which appear in most cases to be solid parti- 

 cles but are too minute for identification. One of them, however, was sug- 

 gestive of rutile. Some of the grains are slightly clouded with a yellowish 

 stain which the microscope is unable to resolve into distinct particles. There 

 are apparently a few fluid inclusions also." 



