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MINERALOGICAL CHEMISTRY. Ii View Article Online / Journal Homepage / Table of Contents for this issue MINERALOGICAL CHEMISTRY. ii. 109 Mineralogical Chemistry. Fibrous Quartz from Rhode Island. ALFREDC. HAWKINS (Amer. Min., 1918, 3, 149--151).--Fibrous quartz resembling asbestos in appearance, and consisting of long, delicate, flexible fibres, fills narrow veins in metamorphic slates at several localities in Rhode Island. It ranges in colour from pure whibe to green. The green colour is due to the presence of admixed actinolite, as shown by microscopical examination and by the following analyses : I, green from Feuner’s Ledge, Crsnston; 11, white from the same locality; 111, green from Portsmouth. SiO,. A1,OR. Fe,O,. CaO. MgO. H,O. CO,. S. Totd. I. 77.15 8.72 7.68 0.70 3.96 1.40 - 0.52 100.13 v 11. 9442 4-68 trace &race 0.16 - - 99.64 111. 91.83 1-61 3.81 0.80 1.37 0.70 0.60 0.12 100.74 L. J. S. Published on 01 January 1919. Downloaded 26/10/2014 03:57:07. Hambergite from Kashmir. R. C. BURTON(Rec. Geol. S.zcrvey Zndia, 1913, 43, 168---172).-C?rystals of harnbergite, together with cookeite, prehnite, tourmaline, beryl, euclase ( ?), and amblygonite, have been found in the granitic dkbris in the Kashmir sapphire mines. They were probably derived from the iieighbouring pegmatites. A description is given of a twinned crystal, Analysis gave : G10. B,OP H,O. Total. Sp. gr. 52.40 [37.39] 10.21 1oo*oo 2.36 L. J. S. Phosphorite from the Island of Juan de Nova, Madagascar. J. ORCEL (Bull. Soc. fmm. Mim., 1918, 41, 104--108).-The phosphate deposits on the small island of Juan de Nova, or St. mristophe, aboutl eighty miles off the west coast of Madagascar, have been formed by the action of soluble phosphates, derived from guano, on the underlying caral-rock. Analysis I is of brown, con- cretionary phosphorite, and I1 of brourn, earthy material of prac- View Article Online ii. 110 ARSTRA4CTS OF CHEMICAL PAPERS. tically the same composition. The latter is worked under the name “leached guano.” The analysis (I) shows an excess of 8.45% CaO, indicating t,he voedckerite formula 3Ca,(P04)2,Ca0 (A., 1912, ii, 565). CaO. 8r0. MgO. Al,03. P,Os. C1. so,. I. 48.63 0.17 1-75 0.15 35-56 0.29 0.56 11. -46.85 n.d. 0.38 35.19 0.14 0.58 Organic Loss CO,. matter. H,O. at 110’. Insol. Total. I. 0.14 1.27 7-97’ 4.00 0-05 100.54 \ 2 11. 10.08 5-35? 0.03 98.57 L. J. S. The Colour Change in Vivianite. THOMASL. WATSON(Ainer. &€in., 1918, 3, 159--161).--The large, pale green crystals of vivianite from Plant City, Florida (A*, 1918, ii, 119), are non- pleochroic and yield a colourless powder. This powder rapidly changes, especially in sunlight, to deep blue, and becomes strongly pleochroic. An unground sample of the crystals showed FeO 42*88%, whilst the finely ground material gave FeO 38.43%. Tho change in dour and pleochroism is thus due to the partial oxida- tion of the iron, and not to inversion as was ah first suggested by the microscopical aspect of &he material. A tabulation of the refractive indices of pale green and of dark blue vivianite from various localities indicates that the oxidation has been accom- panied by an increase in the values of j3 and y. L. J. S. Copiapite in Coal. WILLIAMJ. MCCAUGHEY(Amer. Mzn., Published on 01 January 1919. Downloaded 26/10/2014 03:57:07. i918, 3, 162--163).-A specimen of pale green, fibrous melanterite from the Congo coal mine in Perry County, Ohio, changed in ths course of a year to dull white, and the fibres became brittle. Yellow spots also developed, especially at the points of contact between the melanterite and the associated shale. This yellow material consists of minute, tabular crystals, and is proved by the following analysis and refractive indices to be copiapite, Fee03,5 SO,, 18H20. SO,. Fe,O,. H,O. Insol. Total. a. B. Y* 39.68 29-98 30.45 0.31 100.42 1.525 1.545 1.595 L. J, S. Nasonite from Langban, Sweden. G. AMINOFF(Geol. Fiir. Forh., 1916, 38, 473).-This mineral, hitherto known only from Franklin, New Jersey (A., 1900, ii, 89), has been observed at Lingban in the veins of ‘‘ secondary calcite,” where it is associated with schefferite, native lead, apophyllite, etc. It forms white to pearl-grey lamellar masses, or, less often, hexagonal prisms with View Article Online &TI?TERALOGZ('hL CHEMISTRY. ii. 111 rounded faces. Refractive indices (Na), o = 1.9453, e= 1.9710. Analysis by R. MAUZELIUSagrees with the usual formula Pb,( PbCYI),Ca,( Si20,)3. SiO,. PbO. FeO. JInO. CaO. MgO. C1. H,O. Total. 18.23 67.67 0.04 0.14 11.29 0.20 2.90 0.34 100.71 L. J. S. Anorthite from Japan. 8.KOzu (Sci.h'ep Y'dhokic Imp. Unav,, 1914, Geol. Ser., 2, 7-33).--The results are given of elaborate determinations of the optical constants (refractive indices, optic axial angle, and dispersion of the optic axes) for different wave- lengths of anorthite from three Japanese localities. As these show certain differences amongst themselves, the following analyses, by H. s. \\7~~~~~~~~~,were made of I, aiiorthite crystals from Miyake-jima, one of the Seven Izu Islands south of Tokyo, and 11, crystals from the Tarumas volcano in Holrkaid6. SiO,. Alto,. Fe,O,. CaO. MgO. K,O. Na,O. Total. Sp. gr. I. 44-49 36.00 0.08 19.49 0.04 0.03 0.59 100.72 2.758 11. 44.03 35.93 0.10 18.66 trace 0.07 1-00 100.24 2.757 Barium aiid strontium are absent, and the slight differences in composition cannot be co'rrelated with the differences in the optical constants. I corresponds with Ab3.,An,5.,Cg,.7 and I1 with Ab,.7An,,.,,C"g:!.,0t-,.6. The melting points are 1538O and 1536O k 2O respectively. L. 5. s. Racewinite, a New Mineral from Utah. A. N. \YINCHELL (ECOPZ.Geol., 1918, 13, 611-615).-The mineral occurs as veins and irregular masses in limestone, and also replacing the carbonate portion of calcareous sandstones, near the contact with Published on 01 January 1919. Downloaded 26/10/2014 03:57:07. porphyry in the Highland Boy mine at Bingham, Utah, where it is often intergrown with pyrites and other ore minerals. It is brownish-black with a dull to bright lustre, and somewhat resembles coal in appearance. When freshly taken from the mine, it is bluish-green ; the change in colour to brownish-black takes place slowly throughout the whole mass, and after six months the largest pieces were altered to the centre. The mineral undergoes other remarkable changes in colour. In boiling xiitric acid it is insoluble, but gradually changes to yellowish-brown and translucent. In hydrochIoric acid, it7 is slowly soluble and shows the same change in colour. Thin splinters and particles under the microscope are pale to brownish-yellow. In clove-oil this colour changes first to grass-green aiid then to black, but the same change does not take place in cedar-oil and some other oils. The finely powdered mineral is nearly white with a yellow tinge. The material is coarsely crystalline with no cleavage or crystal-faces; it is friable and the fracture coiichoidal. Sp. 9:. 1.94-1-98, H 24 ; optically biaxial with large angle and negative, IZ. about 1-51. It adheres to the tongue and slakes in water, breaking up with a sharp, audible View Article Online ii. 112 ABSTRACTS OF CHEMICAL PAPERS. sound. Analyses I and I1 by 5. P. HICKEYand C. L. AUSTIN respectively : SiO,. A1.03. Fe203. CaO. MgO. H,O. Total. r. 43-92 23.68 7.37 2.52 0-50 22.04 100.0:: 11. 43.24 23.69 8.05 2.42 0.78 21.80 99.98 A sample of the green, unaltered mineral showed 0.60% FeO. Over sulphuric acid, 7-8% H,Q is lost in one day and 14% after forty-nine days ; this is re-absorbed from a moist atmospf-ex. Other determinations gave the loss at 70° as 8% and at ZOOo as 12.1%. Heated to dull redness, the crystal structure is not destroyed, and the optical characters are not materially altered. L. J. S. New Swedish Minerals = GUST. FLINK(Geo 1. For. Fo~h.,1917, 39, 426-452).--Ektropite forms crusts of small, brown, rect- angular plates on garnet with calcite and barytes in magnetite ore from the Norrbotten mine at L;Pngban. The crystals are mono- clinic (a: b : c = 0.74 : 1 : 0.84, p= 61%’) with a tabular habit parallel to the orthopinacoid and elongated in the direction of the axis of symmetry. They are opaque with a vitreous to silky lustre, but in thin splinters under the microscope, the material is translucent and yellow. D 2.46, H 4, n 1*62--1*63. Analysis I, by N. SAML- BOM, gives the formula 12R8,8Xi0,,7H2O. The mineral is related to caryopilite and neotocite. sio,. Sb,05. PbO. A1,0,. Fe,O,<. FeO. I. 35.02 _. - 0.75 - 5.80 11. 7-75 20.76 - 9.50 3.58 2.44 111. 34.72 - 41-74 - - - MnO. CaO. MgO. H,O. Total. I. 37-20 3-59 7-20 8.89 99.89” Published on 01 January 1919.
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