Geology and Mineralogy. 75 



This is interpreted to stand for 10RO.As 2 O 3 + 10R(OH) 2 where 

 R=MnCa&Mg. Hardness 4, vitreous luster, pale pink streak. 

 Easily soluble in HC1. Basilite a foliated dark metallic bluish 

 looking mineral occurring with hausmannite. In thin folise trans- 

 lucent with blood-red color. An analysis on impure material 

 gave 



Sbo0 5 ivIdo0 3 Fe 2 3 H 2 



13-09 70-01 1-91 15-00 



Sjogruvite occurs in thin lamella in veins and druses with jacobs- 

 ite. Translucent blood-red color. Streak yellow. The analysis 

 gave: 



As 2 5 MnO Fe 2 3 CaO PbO H 2 _ ,„„ ,* 



49-46 27-26 11-29 3-61 1'74 6-81 U 



This brings it very near Arseniopleite previously described by 

 the same author. All of these minerals are however so imper- 

 fectly investigated that it is impossible to say whether they will 

 stand as definite new species or not. Some of them have been 

 determined as such only by qualitative analyses carried out upon 

 material of doubtful purity. All crystallographic and nearly all 

 physical examinations are wanting. Such work in mineralogy is 

 to be greatly deplored as tending to promote confusion and disor- 

 der. — Zeit.f. KrysL, p. 487, vol. xxii, 1894. 



Rittingeaite has been shown by Mlers to be identical with 

 JEanthokonite. The former name thus becomes only a synonym. 

 Also that the mineral is really monoclinic, ang. ft = 88° 47' 

 simulating hexagonal symmetry. In conjunction with this, the 

 analytical work by Prior shows that it is a silver sulpharsenite 

 and not a sulpharsenate. Thus it has the same composition as 

 proustite, the molecule Ag 3 As S 3 being dimorphous {Ibid. 433). 



FranJceite is a new mineral from the mines in the Dept. of 

 Potosi, Bolivia, described by Stelzister. An analysis by Winkler 

 gave 



Pb So Sb S Fe Zu Gang 



50-57 12-34 10-51 21-04 2-48 1-22 0-71 = 98-87; 



the iron and zinc being deducted as pyrite and sphalerite, the re- 

 mainder gives the formula Pb 5 Sn 2 Sb 2 S ]2 . Traces of germanium 

 were also found. Occurs in radiating fibrous or foliated masses. 

 Cleavage in one direction good. H.=2|. Sp. Gr. = 5*55. Luster 

 metallic, opaque, color blackish gray to black. Under the name of 

 "llicteria" is known as an ore. — (Jahb. f. Mm. 1893, vol. ii, p, 



114). L. V. P. 



8. Manuel de Miner alo g ie ; par A. Des Cloiseaux, tome 2d 

 deux. fasc. Paris, 1893. (Dunod.) — The first volume of this 

 work appeared in 1862, the last part of the second volume in 

 1874. Of the plan and scope of the work it is unnecessary to 

 say anything here, it is familiar to every mineralogist of every 

 nationality, and it is a matter of congratulation that the veteran 

 mineralogist, whose services to science have been so great, has 



