G. J. Brush’s Mineralogical Notices. 67 
These ratios are so nearly alike, that the Diana mineral is proba- 
bly gieseckite in which a portion of the magnesia is replaced by 
an | equivalent amount of lime and potash. The oxygen ratio 
By expressed by #8: 2}#:48i: 1H, which gives the form- 
ula (gite-+ 12) Sie4 oH, or more simply (R*, Al, H*)Si. 
he researches of von Hauer and Kenngott show that gie- 
seckite and liebenerite are closely related to each other. They 
are both hexagonal and both have many of the Figg bac: proper- 
ties of the Diana mineral. ey all have nearly the same com- 
Ram as the pinite from Auvergne and from axony as given 
Rammelsberg and Marignac. 
” Pinito ; is stated to be hexagonal by the earlier mineralogical 
writers, but Haidinger* has referred it to the trimetric system, 
and classes it as an altered iolite. Philli ips, however, gives a 
figure of pinite from Puy de Dome with measurements which 
seem to prove it to be fetes onal. Marignac also favors the 
idea that it is hexagonal. But, whatever ‘the fact about pinite, 
the form of liebenerite and gieseckite, like that of the Diana 
mineral, is unmistakably hexagonal. 
e close relation of these minerals in chemical composition 
is seen from the following analyses. 
Si Al Fe Fe Mn Ga Me K Na H 
1. Liebenerite, 4513 3650 263 — — 081 0-75 807 042 4-70 Oellacher. 
2. ie 3656 177 — — — 133 989 0°92 5-06 Mari : 
BS 75 226 — — 158 itr. 645 279 4-75 vy. Hauer. 
4. Gieseckite, Greefland, = 40 2660 — 630 tt — 835 4384 — 676 xed 
4a. 60 700 — ir. — 835 484 — 676 bid 
5. Duns, 4566 3153 O27 O77 > 220 348 Bal O88 6-97 Brush. 
6. Pinite, Auvergne, 4750 31:30 — 392 — — 178 9°05 0-92 503 i 4 
5 ee Pardoux, -92 3229 349 — O11 O51 130 914 — 427 Rammelsb. 
8. “ Mont Brévent, 44:70 3164 — 657 —  — 286 789 095 539 Marignac. 
re 6°S3 2765 — 784 — 049 1-02 6-52 040 7-80 Rammelsb, 
30. 7* ig, 47-00 se — 708 — 0-79 2-48 10-74 107 3:3 ae ie 
« ~ Penig, 48-00 28 — 966 — 075 — 13:35 t— 300 Scott. 
$ Saxony, 46°10 3246 = 497° = = 9-00 0-46 5-45 Rr 
and 2 as quoted by Kenngott in Sitzungsberichte Wien Akad., ix, 59 
3 ¥, Hauer, J ahrbuch k. k. geologische Reichsanstalt, 1858, 147. 
ne adore with iron calculated as Pe, 
5. mean ae viet 
6, 8 and 12, Magna, Bibliothiqu Universelle de Gentes 1847, 159, 
7. Ramm melsberg Min ralogie, aoe 
and 10. ‘iii, 94. 
11. < “ 
This similarity in Bestel composition would seem to eal 
cate a common origin for these pseu cel eg minerals. Tam 
naut endeavors to show that the Greenland gieseckite is altered 
: he does not ae tebe his" opinion by a nalyses. 
‘Ann. Ixvi . Ann. xiii, 149 ¢ Nachtrag, ii, 131. 
i der onion und physicalischen Geologie, i li, 2259. Back: 
Sitzungsberichte Wien 
Akad, ix, 
