MINERALOGY. 473 



Harstig mine, Paj.sberg, Sweden, It occurs in massive forms, having a 

 columnar or fibrous structure, aud shows two uuequal cleavages inclined 

 at an angle of 82.^ degrees. On the basis of an optical examination it 

 is referred to the triclinic system. The color is rose-red and the luster 

 silky. The hardness is 4 to 5, and the specific gravity 3.03. An an- 

 alysis yielded : 



SiOi MnO FeO CaO MgO PbO H2O 



43. G7 37.04 1.11 8.38 0.15 0.77 7.17 = 99.29. 



This gives as the formula 2 (MnCa).Si03+H20, which brings it in com- 

 position near the hydrorhodonite of Igelstrom which is MuSi03-|-H20. 

 In form aud appearance it bears some resemblance to wollastonite and 

 pectolite. It is the most recently formed of the minerals of the Harstig 

 mine, filling cavities between calcite crystals. (Described by G. Flink, 

 in CEfversigt Vet. Akad. Forliandl., Stockholm, 1888, p. 571.) See 

 Ineslte, above. 



Riehecldte — A mineral belonging to the amphibole group, from the 

 island of Socotra, where it was collected by Dr. E. Riebeck, after whom 

 it is named. It appears in slender prismatic crystals, having the char- 

 acteristic cleavage imbedded in granite. The color is black. An analy- 

 sis, after deducting 7.12 per cent, zircon, yielded : 



SiOa FejOa FeO MnO CaO MsO Na.,0 K^O 

 50.01 28.30 9.87 0.63 1.32 0.34 8.79 072 = 99.98. 



It is thus like the pyroxene ffigirito, essentially a silicate of iron sesqui- 

 oxide aud soda, aud is regarded as occupying the same place among the 

 amphiboles. The mineral arfvedsonite has occupied this position, but 

 recent analyses have made it contain chiefly iron protoxide, and if these 

 are- sustained, riebeckite cannot be united with it. (Described by A. 

 Sauer in Zeitschr. deutsch. Geol. Ges., 1888, vol. xl, 138.) 



Bosenbiischite. — See Barkevikite. 



Sulj)hohnh'fe. — A mineral consisting of the sulphate and chloride of 

 sodium. It was discovered by W. E. Hidden on the hanksite of Borax 

 Lake, San Bernardino County, California, and thus far is extremely 

 rare. It appears in rhombic dodecahedrons, which are transparent and 

 of a faint greenish-yellow collor. The hardness is 3.5, aud the specific 

 gravity 2.489. An analysis by J. B. Mackintosh yielded: 



SO3 Cl NajCOs 



42.48 13.12 1.77 



or calculating the chlorine and sulphur as combined with sodiuna only: 



NajSOa XaCl NajCOs 

 75.41 21.62 1.77=98.80. 



This corresponds to 3Na2S04 2NaCl. The name sulphohalite is given in 

 allusion to the unusual composition of the mineral. (Described by W. 

 E. Hidden and J. B. Mackintosh in Amer. Journ. Sci., 1888, vol xxxvi, 

 p. 463.) 



