G. J. Brush on the Chemical Composition of Clintonite. 407 
Arr. XLIIL—On the Chemical Composition of Clintonite ; by 
Gro. J. Brusu. 
THE name Clintonite was given some twenty-five years since 
by Fitch, Mather and Horton to a micaceous reddish-brown min- 
eral occurring at Amity in New York; previous to this, the min- 
eral had been called Bronzite. 
The chemical composition according to Clemson and Richard- 
son is: 
Si Al Mg Ca Mn 2 HAH HF 
1, 170° 876 50 3 107 —— —— 86 — Clemson. 
2, 1985 4475 Fe480 9:05 1145 135 205 455 0-90 Richardson. 
The unaccountable discrepancy between these analyses led the 
Silica, alumina, iron, zirconia, magnesia, lime, potash and soda; 
ho reaction for manganese by Crum’s tes 
A special examination was made to determine the state of oxyd- 
ation of the iron; for this purpose the mineral was decompose 
by hydrochloric acid in an atmosphere of carbonic acid, the re- 
sult proved the iron to be peroxyd. Considerable care also was 
taken in ascertaining whether zirconia was present, as over two 
pr. ct. were found by Richardson ; the iron obtained in the analy- 
Ses was therefore reexamined and in every instance an undoubted 
reaction for zirconia was obtained. On careful examination of 
the specimens with a magnifier, a dark brown mineral resembling 
zircon was found to be intimately associated with the Clintonite. 
A qualitative examination gave all the reactions of zircon,— ! 
Writer is therefore inclined to believe that the zircon obtained in 
the analyses may be due to the associated zircon and not essen- 
ual to the mineral. 
Pe ; 
t Ron ak a ade: 1608, 332, and Jour. f. Prakt. Chem., xiv, 38. 
