156 Scientific Intelligence. 



recent andesites, are absent; only a single case of a rock with 

 nephelite being known. A series of forty-seven plates accompa- 

 nies the text description. These are of excellent execution, well 

 drawn and very delicately colored, and with key plate accompa- 

 nying each, show clearly the many points to be illustrated. 



7. Brief notices of some recently described minerals. — Lans- 

 fokdite. — A white translucent mineral, somewhat resembling 

 paraffin, but having a crystalline structure and vitreous luster ; 

 a prismatic angle of 76° was measured. Hardness 2*5, specific 

 gravity 1*54-1 -692. An analysis by Keeley gave 

 CO., 18-90, MgO 23-18, H 2 57-79 = 99-87. 

 Of the water, the loss over H 2 S0 4 , after 20 hours, was 4*83 p. c, 

 after 48 hours 11*70, after a week 26*33, at 110° C. 12*31, at 185° 

 C. 9*76, at a red heat 9*39. The formula deduced is 3MgC0 3 , 

 Mg(OH) 2 + 2lH 2 0. The mineral was found as a stalactitic 

 growth at the anthracite mine of Lansford, near Tamaqua, 

 Schuylkill Co., Penn. — F. A/Gexth in Zeitschr. Kryst., xiii, 255. 



Horsfordite. — A massive mineral resembling native silver in 

 color, with high luster, but soon tarnishing. Hardness 4-5, 

 G. = 8*812. An analysis gave 



(f) Antimony 26-86. Copper 73-37 = 100-23 

 which corresponds to a compound between Cu 5 Sb and Cu 6 Sb, 

 very near to Cu n Sb 2 . It is thus related to some forms of dys- 

 crasite, also to algodonite. It occurs as an extensive deposit 

 near Mytilene in Asia Minor. — A. Laist and T. H. Norton in 

 Arner. Chem. Journ., x, 60. 



Hohmannite, Amarantite. — Described as two independent 

 hydrous iron sulphates, occurring with copiapite from Chili. 

 Hohmannite is a chesnut-brown massive mineral with a fibrous 

 structure. Hardness 3, specific gravity 2 -24. An analysis gave 



S0 3 30-88, Fe 2 3 4005, H 2 29-63 = 100-56 

 for which the formula 2Fe 2 3 , 3S0 3 + 13H 2 is calculated. Am- 

 arantite occurs in microscopic crystals of an orange color. The 

 analysis gave 



S0 3 37-26, Fe 2 3 35-58, H 2 27-62 = 100-46 

 leading to the formula Fe 2 3 , 2S0 3 + 7H 2 0. A later trial of 

 hohmannite gave a result nearly identical with this, making it 

 probable that the two minerals have really the same composition 

 and are identical, though occurring in a different form. A. Fren- 

 zel in Min. JPetr. Mitth., ix, 397, 423. 



Quenstedtite, BfJCKiNGiTE. — In a preliminary notice of some 



iron sulphates from Chili, the name Quenstedtite is given to a salt 



occurring in reddish-violet tabular crystals resembling gypsum. 



They belong to the monoclinic system and have the composition 



2Fe0 2 H + 8Fe 2 (S0 4 ) 3 + 10aq. 



Btickingite occurs in dark brown thick tabular crystals belong- 

 ing to the triclinic system. The formula given is 



2Fe 2 (30 4 ) 3 + 2H 2 S0 4 + 7FeS0 4 + 60aq. 

 — G. Linck in Jahrb. Min., vol. i, 213, 1888. 



