Palmer — Arizonite, Ferric Metatitanate. 355 



pure titanic oxide. The latter is apparently present in the 

 mineral in the free state. This view accords with Dr. Wright's 

 observation that the mineral contains a small quantity of 

 anatase. 



The following analytical results were obtained by decom- 

 posing the mineral with sulphuric acid : 



Analysis. 



Per cent Eatio 



T , , , ( TiO Q 0-56 " " 



Insoluble ] Si0 J r02 u u 



f Fed '10 " " 



| Fe 2 O s 38-38 " '" 1- 



Soluble { Ti0 2 . 58*26 " " 3-03 



| H 2 0- 110° -18 " " 



^H 3 O + 110,° 1-02 " " 



100-12 " " 



The close ratio of ferric oxide to titanic oxide, viz., 1 : 3*03, 

 indicates that the mineral is really ferric metatitanate, 

 Fe 2 3 .3TiO, or Fe 2 Ti 3 9 . Moreover, the crystallographic de 

 terminations strengthen the view that this titanate of iron can- 

 not be assigned to any known species, but is entirely new. I 

 propose to name it Arizonite. 



Arizonite is apparently without cleavage. The fracture is 

 subconchoidal. It is brittle, with hardness between 5 and 6, 

 specific gravity 4*25. Fresh fracture surfaces are dark steel 

 grey in color and metallic to submetallic in luster. Its streak 

 is brown. The mineral is opaque and is not magnetic. It is 

 partially decomposed by hydrochloric acid. The filtered solu- 

 tion, containing ferric chloride, responds readily to the oxida- 

 tion and reduction tests for titanium. 



There appears to be no authentic prior record of the occur- 

 rence in nature of a simple ferric metatitanate (Fe 2 3 .3Ti0 2 ). 

 The literature furnishes, however, a few examples of the exist- 

 ence of this form of titanic iron, either admixed or combined 

 with ferrous titanate (FeO.Ti0 2 ), the usual form of natural 

 titanic iron. 



Rammelsberg- recognized that a variety of iserine, described 

 by him as of uncertain crystallographic form, is a titanate of 

 ferrous and ferric oxides. Upon readjustment of the analyti- 

 cal data as cited by Rammelsberg, it appears that his mineral 

 consists essentially of 60 per cent ferrous titanate (FeO.Ti0 2 ), 

 ilmenite, and 40 per cent ferric titanate (Fe 2 3 .3Ti0 2 ), arizonite. 

 Attention is also called to the low specific gravity of this iser- 

 ine, viz., 4*4. This is much under the specific gravity of the 



*Pogg. Ann., civ, 532, 1858. 



