Geology and Mineralogy. 259 



Quktenite, Gordaite. — In a paper upon the various ferric 

 sulphates from Chili, to which attention has been directed re- 

 peatedly of late, Frenzel, besides notes on other species, describes 

 two new ones. Qnetenite occurs at the Salvador mine in Quetena, 

 west of Calama. It is massive, of a reddish-brown color, hard- 

 ness = 3, specific gravity =2 , 08-2 , 14. An analysis gave: 



S0 3 37-37 Fe 2 3 22'70 MgO 5-92 H 2 34-01 = 100 



For this the formula MgS0 4 , Fe 2 S 2 9 + I3H 2 is calculated. 

 Gordaite occurs with sideronatrite and is related to it in compo- 

 sition. It is found in indistinct crystals, perhaps triclinic, and in 

 small foliated masses with fibrous structure. It is colorless to 

 white or light gray, luster vitreous, hardness = 2'5 to 3. 

 Specific gravity =2 61. An analysis gave: 



S0 3 50-85 Fe 2 3 19-42 Na 2 22 36 H 2 7-33 = 99-96 



The formula is 3Na 2 S0 4 , Fe 2 S 2 9 + 3lI 2 0, which brings it near the 

 ferronatrite of Mackintosh. — Mm. JPetr. Mitth., xi, 214-223. 



Lussatite. — A crystalline form of silica described by Mallard 

 as forming an envelope over colorless quartz crystals in the bitu- 

 men deposit at Lussat near Pont-du-Chateau. It has a fibrous or 

 fibrous-lamellar structure, the fibers being perpendicular to the 

 surface of the crystal. They are doubly-refracting in the direc- 

 tion of their length and have the opposite optical character (-)-) to 

 chalcedony. The specific gravity is 2 - 04 and the mean index of 

 refraction for D T446, in both points approximating to the char- 

 acter of opal. Chemically, it consists of pure silica for the most 

 part, but in part mixed also with amorphous silica or common 

 opal. Its occurrence at a number of localities, associated with 

 opal is noted.— C. R., vol. ex, 245, Feb. 3, 1890. 



12. On the supposed occurrence of Phenacite in Maine — a cor- 

 rection ; by W. S. Yeates (communicated). — In the April number 

 of this Journal, I announced that I had identified phenacite from 

 Hebron, Maine ; and that, among other planes, I had observed 

 the basal plane, O. This announcement was based upon a pre- 

 liminary examination, the angle between the adjoining planes of 

 a pyramid, 156° 46'^, being practically the same as that between 

 f-2 and f-2 of phenacite, viz : 156° 44'. The apparent infusi- 

 bility of the mineral, when first examined, coupled with the strik- 

 ing resemblance of the crystal to phenacite in habit, served further 

 to mislead. A more careful examination, recently made by me, 

 disclosed the fact that the mineral was not phenacite ; and a 

 quantitative analysis, by Mr. L. G. Eakins of the IT. S. Geological 

 Survey, has proved it to be apatite. The plane, which was at 

 first taken for f-2 of phenacite, is the pyramid |-. The unusual 

 fiat habit of these apatite crystals is well worthy of note. 



TJ. S. National Museum, Aug. 7th, 1890. 



13. Tableaux des Mineraux des Roches, resume de leurs pro- 

 pri'etks optiques, cristallographiques et chimiques par A. Michel- 

 Levy et A. Laoroix. Paris, 1889. (Baudry et Cie.) — These 

 tables form a useful supplement to the well known work of the 



