this species, and in accounting for their similarity of crystallization, deduces as follows their atomic volumes.-(Pogg. Ann., lxxxi, 31.) He then observes that the numbers 1464, 1808, 1850, 2217, 3013, have the relation (correcting his 1-25, by substituting 1-26) 1:1-24: 1.26: 1:51:2:06, or very closely 1:1:1:24:5:6:8. But let us now divide these numbers by the number of atoms of the elements, and we shall find the atomic volumes, as thus deduced, very closely equal. This equality is certainly very remarkable, and the identity of crystallization is attributed to it with good reason. We also remark that the number of atoms 33, 41, 42, 50, 68, have to one another the ratios 1:1-24:1-27:1:51:2·06, which are coincident, as will be observed, with the ratios obtained by Rammelsberg for the atomic volumes. The ratios 4: 5: 6:8, which this chemist deduces, are in fact therefore only the ratios of the number of atoms, 33:41:50: 68. ART. XXIV.-Mineralogical Notices. No. III. 1. New Species. Gurolite, a new mineral; T. ANDERSON, (Phil. Mag. [4], i, 111.) -Occurs on Skye, at Storr, nine miles from Portree, in basalt; it is associated with apophyllite, stilbite and laumonite, though found in the finest specimens where these minerals do not abound. The name gurolite (more correctly gyrolite,) alludes to the spherical * In the first formula, R3 contains 6 atoms or molecules; Si2, 8; 3, 15; 3Si 12; making in all 41. form of its concretions, and is from rvoos, orbiculatus. Structure radiating, and surface of the concretions appearing striated owing to the plates of which it is formed rising to irregular distances above the surface; cleaves easily parallel to the plates. Color white; lustre vitreous, passing into pearly on exposure; perfectly transparent in thin plates. Very tough. Hardness between 3 and 4. B.B. yields water, swells up and separates into thin pearly or silvery plates. On charcoal swells up, splitting into thin lamina and fuses to an opake enamel. With borax, yields a transparent colorless glass; with soda fuses with difficulty to an opake mass. Readily attacked by hydrochloric acid. Composition according to T. Anderson, He thence deduces the oxygen ratio for the lime, silica and water, (considering the other ingredients as unessential,) 1:3: 13, and the formula 2CaSi+3H. The formula requires a little less lime and more silica and water, which discrepancy Mr. Anderson attributes to partial efflorescence. The ratio of lime and silica is the same as in Edelforsite. Its efflorescence and crystallization in plates distinguish it from dysclasite. Aræoxene, a new vanadate of Lead and Zinc.-KOBELL received this new mineral through Prof. Döbner. It was found at Dahn in the Palatinate, with galena, and had been considered a chromate of lead. It occurs massive but imperfectly crystalline, with some traces of a columnar structure. Color red, darker than crocoisite, with a brownish tinge; streak pale yellowish. H.-3. B.B. on coal fuses easily with intumescence, and yields an arsenical odor with a globule of lead, the latter being larger with soda. With borax fuses in the reduction flame to a bright green glass, which in the oxydation flame becomes gradually light olive green, then clear yellow, and on cooling changes to a pale greenish tint. Heated with concentrated muriatic acid, the powder easily decomposes, and the liquid is first yellow, then brownish, and after giving out chlorine, emerald green. On adding spirits of wine, heating it, and pouring off from the solution the separated chlorid of lead, it is still green; but on concentrating it by means of a vapor bath and then diluting it with water it takes a fine skyblue color. In this characteristic, it is like other allied vanadium compounds. Von Kobell found in the mineral 487 p. c. of oxyd of lead and 16-32 of oxyd of zinc. The vanadium lead ore analyzed by Damour contained only 6:34 p. c. of oxyd of zinc. (J. f. pr. Chem., 1, 496.) Enargite, a new_ore of Copper; A. Breithaupt, (Poggend. Ann., lxxx, 383.)-Enargite comes from Morococha, district of Jauli, in the Cordilleras of Peru, at a height of 14,000 feet (French), and also from a mine near Freiberg, along with other copper ores. It occurs in Peru abundantly in large masses containing occasional small druzes of crystals, imbedded with tennantite in crystalline limestone. The Freiberg mine affords it in acicular crystals, which are distinguished from other glances by the prismatic cleavage. Lustre metallic, slightly imperfect; color iron-black; streak black; H.3 or that of calc spar; G.=4·43-4·445; easily pulverized. Crystallization trimetric; the crystals presenting the planes of a rhombic and rectangular prism; rhombic prism (P)=98° 11': cleavage prismatic, perfect; brachydiagonal and macrodiagonal distinct; basal indistinct; octahedral (P) in traces. Fracture uneven. B.B. in a glass tube, decrepitates and gives with little heat a sublimate of sulphur; in a stronger heat, fuses and produces sulphuret of arsenic of a reddish yellow color; on charcoal it gives out arsenous acid, oxyd of antimony and oxyd of zinc; and in the reduction flame, it finally yields with borax a globule of copper. Analysis of the Peruvian ore afforded Plattner, (ibid, p. 386) S Fe Zn 0.565 0.228 Ag 0.017 99-449 This gives the ratio for the sulphur,-the arsenic and antimony, and the copper, iron and zinc, 1605: 197: 1214, or very nearly 8:1:6, whence he deduces the formula (writing Cu for copper and the allied metals) or perhaps [8Cu S+As S] + [2€u S+ As S®], 3(Cu, Fe, Zn) S + (As, Sb) S3, equivalent to sulphur 32-64, arsenic 19-11, copper 48·25. Carmine Spar; F. SANDBERGER, (Pogg. Ann. lxxx, 391.)— Carmine spar is a red mineral occurring with cube ore (Beudantite) at Horhausen in Saxony, in quartz and brown iron ore. Crystallization not distinct, probably rhombic; occurs in clusters of fine needles and spheroidal forms of a columnar structure; cleavage parallel to the faces of a rhombic prism. Lustre vitreous, but pearly on a cleavage face; color carmine to tile-red; powder reddish-yellow; translucent; brittle; hardness 2.5, or between rock salt and cale spar. B.B. on charcoal fuses easily to a steel gray globule, giving out arsenical vapors. With soda, yields a globule of lead, and with borax the reaction of iron is obtained. In a glass tube over a spirit lamp, does not change. Heated in concentrated muriatic acid it dissolves very easily to a gold-yellow fluid, in which chlorid of gold does not deposit metallic gold; soluble in nitric acid. From these and other trials, it is inferred that the mineral is an anhydrous arsenate of oxyd of lead and iron; the quantitative relations have not been determined. Dechenite, a vanadate of Lead; Dr. C. BERGEMANN, (Pogg. Ann. Ixxx, 393.)-Dechenite comes from the Lauter valley in Rhenish Bavaria, near Nieder-Schlettenbach, where the rock is the "bunter sandstein." It occurs in small botryoidal masses, having a crystalline texture, and presenting when purest a dull red color. There appear to be indications of a rhombohedral cleavage. In these masses there are occasional wart-shaped grains of a more yellow color. The streak is always yellowish. Lustre of fresh fracture greasy; G.=581; H.=4, or that of green lead ore. B.B. alone in the platinum forceps it fuses easily to a yellowish glass; in a glass tube gives no water; on charcoal, does not decrepitate like the known vanadate ore, but fuses easily to a yellowish green pearl, which yields a slag containing some grains of lead. With more of the assay, the odor of arsenic is sometimes given off. With salt of phosphorus and borax, gives the reaction of vanadic acid. Soda yields a white enamel containing grains of lead. According to the examinations, the mineral consists of The first two analyses afford the oxygen ratio for the base and acids 1:3, equivalent to the formula Pb V≈ vanadic acid 45·33, lead 54.67. Octahedral oxyd of Antimony.-M H. DE SENARMONT describes (Ann. Ch. Phys. [3], xxxi, 504,) an oxyd of antimony of octahedral forms from Sensa, near the sources of Aïn-el-Bebbouch, (Province of Constantine.) At one locality, the oxyd is in masses often cavernous, composed of capillary filaments parallel or a little divergent, and pearly or adamantine in lustre; it is the prismatic species. But at another mine called Mimine, the same oxyd exists in saccharoid masses, granular or compact, having cavities covered with octahedral crystals that are sometimes more than a centimetre in diameter. Several admitted of measurement and proved to be the regular octahedron, the cleavage octahedral, but a little difficult. The composition is that of the pure oxyd, or oxygen 15-68, antimony 84-32. G. =5.22-5-3, while that of the prismatic oxyd is 5.56. Hardness less than that of calcite. Colorless; transparent; strongly refracting without regular action on polarized light. Specific gravity of the massive variety 5.23, and color mostly grayish; contains sometimes less than 1 per cent. of lead, and there may be 1 to 3 per cent. of gray clay. It is probable, from the existence of thermal waters in the soil below, that these crystals were formed in the humid way. Oxyd of antimony is then dimorphous. Arsenous acid presents the same forms. Wöhler* observed prismatic crystals which were recognized as like those of oxyd of antimony by Mitscherlich; while octahedral crystals are readily obtained by sublimation or by solution. [Senarmontite is an appropriate name for this octahedral oxyd.] Mineral species described by Prof. C. U. SHEPARD, (Proc. Amer. Assoc., 4th Meeting at New Haven, p. 311.)-1. Dysyntribite. Occurs in considerable masses in St. Lawrence county, New York, and has some resemblance in appearance to serpentine. It is found at Rossie, and at Natural Bridge in Diana, and is usually in connection with the specular iron of the region. It is massive, granular, tough, almost dull, with an even splintery fracture; color dark green, grayish or yellowish, sometimes mottled with red and black. H. 3.5-4. G. 2.76-2.81. B.B. in thin fragments fuses to a white porcelainous mass. In an open tube yields water. Contains according to Prof. Shepard Si Fe Ca, Mg trace 99-49 whence he deduces the formula 16A1 Si+Fe Si+9Ĥ. [The dysyntribite is somewhat remarkable for its external resemblance to serpentine, while at the same time it is aluminous in composition. The specimens are very various in appearance, and look much more like a rock than a mineral species, (as might be inferred from the improbable formula given,) appearing to be a result, to some extent, of metamorphic action.] 2. Rutherfordite, (ibid, p. 312.)-Occurs in crystals and grains at the gold mines of Rutherford Co., North Carolina, along with rutile, brookite, zircon and monazite. Monoclinic; M: M = 93°. Cleavage, none. Fracture conchoidal; lustre of fracture shining and resinous; color yellowish brown; opake. H.-6.5; G.=5.585-69. B.B. in a glass tube cracks, glows as if on fire, emits much moisture and turns yellow; alone infusible; with borax forms slowly a clear yellow glass. According to trials by Prof. Shepard, it is supposed to contain titanic acid, oxyd of cerium and possibly oxyd of uranium and yttria. 3. Paracolumbite, (ibid, p. 313.)-Occurs a mile southwest of Taunton, Mass., in minute quantities in a boulder of granite containing a peculiar greenish-white feldspar. Massive, in grains and short irregular seams; iron-black, sometimes with a tinge of purple, and a black streak; imperfectly metallic; opake. H. about 5. From his examinations, Prof. Shepard infers that the mineral seems to be composed of the oxyds of iron and uranium in combination with a metallic acid, which is not the titanic. * Wöhler on the dimorphism of arsenous acid, Pogg. Ann., xxvi, 177. SECOND SERIES, Vol. XII, No. 35.—Sept., 1851. 27 |