356 Palmer — Arizonite, Ferric Metatitanate. 



more common varieties of ilmenite (4*7 to 4*9), and is only 

 slightly above that of arizonite (4*25). 



Even more closely related to arizonite is a titanic iron sand 

 from Brazil, described by J. B. Mackintosh.* The numerical 

 data there given for the Brazilian sand are : 



Ti0 2 59-20 



Fe 2 3 '__ 32-11 



FeO 4-90 



MnO ; 1-73 



SiO„ 1-16 



99-10 



Specific gravity 4-2. 



Mackintosh's results indicate that the mineral was a mixture 

 of about 85 per cent ferric titauate, with 15 per cent ferrous 

 titan ate. The concordance of the specific gravity of the Bra- 

 zilian sand with that of arizonite, and the preponderance in it 

 of ferric titauate, suggest the propriety of regarding this sandf 

 as an impure arizonite rather than as a variety of ilmenite. 



Chemical Laboratory, 



U. S. Geological Survey. 



♦This Journal, xxix, p. 342, 1885. 



f Dana, System of Mineralogy, 6th edition, page 218. Ilmenite, Brazil, 

 Analysis No. 5. 



