250 New Minerals from Arkansas. 
1. Arkansite.* 
- ‘Primary form. Right rhombic prism. M 
_ on M, 101°. 
Stents form. Mone, 133° 45’, 
c on c over 
hee, et 
edge x inclines to edge 
| x at about 94°. | / 
Cleavage indistinct. Surface, M brilliant, c less so, d brilliant, 
though drusy, and channelled vadcally. Fracture sub-conchoidal, 
to uneven, Lustre metallic. Color dark steel-gray to iron-black. 
Faces ¢ tarnished blue, like specular iron. Streak dark ash-gray. f 
The powder (until it becomes perfectly fine) shows points with 
a metallic lustre. 
Brittle. Hardness = 7-0—7‘5._ 
When heated in a glass tube, the mineral affords no ) traces of 
moisture, or of hydro-fluoric acid. . Alone, before the blowpipe, a 
on charcoal, it is unalterable. With borax, it enters SOD into 
fusion, and gives a transparent, deep yellow glass. - 
x Ssodey fom the State in which: iti is fou ak es a 
{ None of these angles were obtained from perfect reflections. 
t A crystal weighing 0-68 gr. in the state of powder, was boiled for an hour in 
sulphuric acid, during which it underwent decomposition, The yellowish green 
insoluble matter separated, was thrown upon the filter and subsequently ignited. 
Its color became pale straw-yellow. | Its weight was. 0-32 gr. It afforded the reac- 
tions of titanic acid. The sulphuric solution irons been found to afford a pre- 
anes with sulphate of potassa, which was soluble by addition of more of the 
rated solution of sulphate of potassa) was precipitated, ignited and = 
Ite amounted to 0-28 gr., and had the properties of yttria, aaa it is possible there 
might have air rae intermixture of zirconia and thorin 
a second trial, 1-68 grs. were fused with 12 grs. bisulphate potassa. The re- 
sulting mass aoe a thint tinge of yellow. It was boiled in excess of water 
which a fine, white, heavy powder was precipitated. Mingled with this powder 
was an saother, rather heavy, enc ites grayish white matter, in a quantity, 
which remained behind in the basin as the other was removed to the filter by 4 
stream from the wash-bottle. Sulphuric acid was boiled upon it cheers produ- 
cing any change; but it afterwards slowly disappeared on being. digested with 
‘ydrochloric acid. From a portion of this solution, ammonia threw down a pre 
cipitate, resembling yttria. “The titanic acid, separated from the original sulphurie 
—s > Wei — after ignition, 1-14 gr., or 67 p. ¢. 
‘my examination went, (which. was restricted for want of material to 
enisiin: were at the time, 
in Arete ‘to regard the 1e substance in question as a titanate of ytrit 
which neither lime, oxide of cerium, iron or manganese are present. 
' 
‘ 
