1890.] Mineralogy and Petrography. 853 
diorites, porphyrites, quartz-porphyry, andesites, and trachytes of 
various kinds, phonolites, augitites and tufas. Lacroix ® announces 
the discovery of a peculiar rock, composed of garnets, quartz, ortho- 
clase, oligoclase, nitite, and diaspore, occurring in blocks cast from a 
volcano near Bournac in the Auvergne. r. Nason ? gives a brief 
description of the crystalline rocks occurring in the Highlands of New 
Jersey. 
New Minerals. —In addition to the numerous new minerals lately 
discovered by Börgger in the Scandinavian Peninsula, five others have 
recently been described. These latter are from Sweden ; the discov- - 
ery of them is due to Igelström.? Talcknebelite, from the iron mine 
Hillàng, Ludvika Parish, Gouvernement Dalekarlien, is associated 
with small red garnets. In appearance it resembles zge/szrömite, but is 
lighter and has a pearly lustre on a fresh fracture. In composition it is 
a magnesium bearing knebelite as follows: SiO,— 33.1; FeO = 42.6; 
MnO 91.6; MeO= 47, Ferrostibian has been found imbedded 
in massive rhodonite at the Sjégrufvan Mine, Grythyttan, Oerebo. 
The crystals are quite large. They are probably monoclinic, and 
bounded by oP, oo Pæ and »P&. They are black and opaque, 
with a brownish-black streak, and are weakly magnetic. They have a 
hardness of 4, and in thin section are blood red incolor. The mineral 
dissolves with great difficulty in the usual reagents. An analysis gave: 
SiO, (MgCa)Co,  Sb,O, FeO Mno H,O 
2.24 2.14 14.18 22.60 46.97 9.19 
Regarding the silica cw NE as impurities, and the manganese 
and iron as in the “ ous ° condition (which could not be proven), 
the analysis may be expressed by the formula ro RO. Sb,O, 4- 1o (RO. 
H,0).—— Pleurasite is a hydrate arsenate from the same mine. It is 
implanted in arseniopleite. It is bluish-black and opaque, but in thin 
section becomes pale red. It has a half metallic lustre, a black streak 
tinged with red, and a hardness of 4, and is very weakly magnetic. It 
dissolves readily in dilute hydrochloric acid, and yields a yellow solu- 
tion. Analyses have not yet been made, but qualitative tests indicate 
that it is a hydrated manganese iron arsenate, containing some anti- 
mony. ‚Stibiatite, also from the same mine, occurs in small crystals 
imbedded in polyarsenite and in irregular grains in veins of various 
minerals cutting the manganese ores of the mine. The crystals appear 
8 Bull. Soc. Fran, d. Min., Jan. 1890, p. 7 
9 Ann. Rep. State Geologist of New Jersey for 1889, p. 30. 
9 Neues Jahrb. f. Min., etc., 1890, I., p. 248. 
