| 
| 
W. T. Repper—Pseudomorph after Anorthite. 365 
“ied G.=3-06-3°10. Color light bluish green to greenish 
Ww 
Fusible with some difficulty to a slightly vesicular glass. 
Partially attacked by hydrochloric acid without gelatinizing. 
Oxygen. 
Composition: Silica. ...........-.-- 39°73 21:19 4 
A swe» 82°53. 15°46 
Iron kenga sie cilia 2°80 aut rueaos 
Bs agnesia ...---.----- 144 57) 
: SES CS | RA 9 j 
Sod ee ee SS tes 43 “kL 5°80 1 
Potash << ee "85 
SRO oc 3°65 
100°52 
I have to remark that I have reason to consider the magnesia 
too high. There is probably only a trace. If so, the oxygen 
ae. would be 21°19: 16: 5-23, still nearer the anorthite ratio of 
3:1, 
Though the crystalline form and the composition would make 
it a Setaeeee anorthite, the high specific gravity ae i 
which M awes was so kind as to make for 
When observed ander the microscope, it shows that the mineral 
18 com a congeries of smal] itigeg which produce no 
the actual crystals of the new mineral, which on the’ surface 
Were able to ras of their form. What the latter actually are 
it is impossible to determine. 
ehem, Pa., Sept. 16, 1878. 
Tn the Report of Mr. G. W. Hawes on the “Mineralogy and gg. - 
New Ham a mh ” its — gives the dotiyving analysis of altered 
Snorthite of 4 “diabase,” at East Hanover, in that S$ tSilioa 
°252, alumina 3 iron aokicionh xide 1- 10, be pau 0-30, lime 2-20, ada S 77, 
Ree v3; ‘wee “ 67—99- 12: G.=2°96. It is a potash-bearing pseudomorph, 
® that described by Roepper, with Sectenip high specific gravity; but instead 
of having the removed calcium replaced by an equivalent proportion of a 
included in the protoxides, 1 ag J.D. D. 
