PALACHE. — EPIDOTE CRYSTALS FROM ALASKA. 533 



n (Til) always present, often large, brilliant, and striated. The only 

 form found in the re-entrant angles rarely found on twin crystals. 



a (212) present on one crystal only (figure 7) as a large, fairly 

 bright face. 



F (554), Z (232), <I> (353), c/> (T21), 8 (T41), and E (T51) are pyra- 

 mids of the zone [Til to 010]. Unimportant forms but several of them 

 sometimes present on single crystals as shown in the drawings. F (454), 

 a rare form for epidote, has been reported heretofore only from Pers- 

 berg, Sweden* by Flink ; he determined it hy a single bright face in two 

 zones, no angles being given. It was found with a single face on each 

 of two crystals and was measured as follows : 



Measured. Quality. Calculated. 



<p P P 



354 -160° 40' 67° 21' fair -1 60° 43' 67° 18' (010 as pole) 



128° 01' 29° 33' fair 128° 18' 29° 27' (normal position) 



<t> and 8 were determined solely by contact measurements ; Z and <£ 

 by contact measurements and zonal relations. 



q (221) often present, sometimes large, always dull. 



O (o44), j (755), X (322), y (211), and R (411) are pyramids of 

 the zone [Til to 100]. Of these forms y alone is common; O and j are 

 new to epidote and X and R are rare. 



O was measured on three crystals (two of them twins) with six faces 

 as follows : 



Measured. Quality. Calculated (010 as pole). 



Average -<t>'-±<t> I _ 42 ° 07' 39° 33' -42° 37' 39° 06' 



or 180 — c/> ) 



The agreement of measured and calculated angles is not very close, 

 but the form seems assured. 

 J was measured on two twin crystals with three faces as follows : 



* Biliang t. K. Sv. Vet. Akad. H. Stockholm, 12, No. 2, 1886. 



