An Elementary Treatise on Mineralogy: Comprising an Introduction to the ScienceW.D. Ticknor & Company, 1844 - 662 páginas |
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An Elementary Treatise on Mineralogy: Comprising an Introduction to the Science Robert Allan,William Phillips,Francis Alger Sin vista previa disponible - 2015 |
Términos y frases comunes
alumina analysis antimony arsenic arsenic acid atom barytes Berzelius Beudant borax brittle brown carbonate cerium charcoal cleavage parallel cobalt color colorless conchoidal consists constitution contains Cornwall crystalline crystals cube dodecahedron earthy edges felspar fibrous flame Formula fracture fuses glass globule goniometer green grey heat imbedded intumesces Klaproth lamellar laminæ lead lime lustre magnesia magnetic manganese masses matrass melts metallic mica mineral Mineralogy nearly nitric acid numbers Oblique rhombic prism occurs massive octahedron opake oxide oxide of iron oxygen peroxide of iron phosphoric planes potash primary form prism Prismatic Prof protoxide of iron Protoxide of manganese pyramids pyrites quartz replaced resembles resinous rhombic dodecahedron rhomboid Right rhombic prism rocks Saxony silica silver six-sided prisms soda solid angles soluble sometimes spar species specific gravity specimens streak strontian substance sulphate sulphuret terminal Thomson translucent transparent variety veins yellow yields zinc
Pasajes populares
Página xxvi - These planes are said to be similar, when their corresponding edges are proportional, and their corresponding angles equal. Edges are similar, when they are produced by the meeting of planes respectively similar at equal angles; and angles are similar when they are equal, and are contained within edges respectively similar. Sometimes it happens that the crystal is bounded in all directions by perfectly equal and similar faces, as is seen in the cube, octohedron, and rhombohedron. Such forms are distinguished...
Página 190 - ... portion of the contents of the old species of feldspar, in which, from its wide distribution and known applications, mankind are more generally interested. Its crystals and crystalline masses yield to cleavage parallel to the planes of a doubly oblique prism, which presents, by the reflective goniometer, in one direction, four angles of 90° ; in another, four, alternately of 59° 25...
Página lxxxii - The same number of atoms combined in the same way produce the same crystalline form, and the same crystalline form is independent of the chemical nature of the atoms, and is determined only by their number and relative position.
Página 38 - It occurs in aggregated crystalline masses, deeply striated, or in separate crystals, of several varieties of form, and sometimes in that of its primary crystal, an oblique rhombic prism, of which the inclination of the terminal plane is from one acute angle to the other. It is white, sometimes with a tinge of red, and is translucent, and bard enough to scratch glass.
Página 147 - Shaw, use steatite in their baths instead of soap; and it is confidently asserted that the inhabitants of New Caledonia either eat it alone, or mingle it with their food. Humboldt says, that the...
Página lx - Haiiy have shed over mineralogy a purely philosophical luster which indeed has been one of the chief causes of raising the study to the rank of a science ; this he has done by showing the consonance of the laws of crystallization with rigid calculation: he has proved that in crystallization there is a natural geometry.
Página xxv - The circumference of every circle is supposed to be divided into 360 equal parts, called degrees ; each degree into 60 equal parts, called minutes ; and each minute into 60 equal parts, called seconds.
Página xxvii - Axis of a crystal — The lateral planes surround its axis, which is an imaginary line passing down the middle of the prism from the centre of the upper to that of the lower terminal plane.
Página 6 - ... iron and manganese which it contains : it becomes white and opalescent by long exposure to heat. The best amethysts are brought from Cambay, in India, from Siberia, Ceylon, and Persia, where they are found both lining the cavities of geodes and in rolled masses ; of inferior transparency and hue, they occur in Sweden, the Hartz, Bohemia, Transylvania ; in agate balls at Oberstein, in Germany ; in large crystalline groups near Cork ; and in several parts of the United States.
Página 633 - Dfusy, has been adopted from the German term drusen, for which we have no English word. The surface of a mineral is said to be drusy when composed of very small prominent crystals nearly equal to each other; it i