640 JA Le VOGT 
or perhaps a little below 1150° for the last remnant of sulphides, 
consisting of chalcopyrite with some pyrrhotite and some pent- 
landite. 
Fic. 38.—Photomicrograph between Fic. 39.—Drawing (8:1) 
crossed nicols (15:1). 
Pyrrhotite-olivinite from Bruvand (cf. Fig. 37). Two different portions. 
Fic. 40.—Photomicrograph (17:1) Fic. 41.—Photomicrograph (17:1) 
Pyrrhotite-hypersthenite from Romsaas (Fig. 40) and Messel, near Arendal 
(Fig. 41). In Figure 40 besides pyrrhotite there is only hypersthene. In Figure 41 
besides hypersthene there is also a little labradorite (upper left). In Figure 41 two 
small holes in the thin section appear white. 
For an olivinite, consisting of predominant olivine (0.12 
Fe,SiO,:0.88 Mg,SiO,) and a little orthorhombic pyroxene 
