Rutilated quartz

When quartz forms after or at the same time as another mineral, this can result in one mineral being inside, or included, in the other. Individual crystals of one mineral can be visible within another material, as with rutilated quartz, or one material may be evenly distributed throughout another, as... 

Rutile (titanium oxide) Rutilated quartz Needle stone Venus hair stone Sagenite Colorless to smoky quartz, often as crystals, with needle-shaped yellow, red, or brown crystals of rutile randomly scattered or in radiating sprays... 

Similar diffiisivities were obtained for both synthetic and natural quartz, and for a range of Ti source materials, including natural titanite powder and rutile-quartz single crystal diffusion couples. Although Ti diffusion appeared to be slightly slower in the direction normal to c, this difference was not great. 

Germanium(IV) oxide occurs in two forms one has a rutile lattice and melts at 1359 K whilst the other has a quartz lattice and a melting point of 1389 K. It can be prepared by oxidation of germanium using, for example, concentrated nitric acid, or by the hydrolysis of germanium tetrachloride ... 

The strength of dispersion interaction of a solid with a gas molecule is determined not only by the chemical composition of the surface of the solid, but also by the surface density of the force centres. If therefore this surface density can be sufficiently reduced by the pre-adsorption of a suitable substance, the isotherm may be converted from Type II to Type III. An example is rutile, modified by the pre-adsorption of a monolayer of ethanol the isotherm of pentane, which is of Type II on the unmodified rutile (Fig. 5.3, curve A), changes to Type III on the treated sample (cf. Fig. 5.3 curve B). Similar results were found with hexane-l-ol as pre-adsorbate. Another example is the pre-adsorption of amyl alcohol on a quartz powder... 

Adularia is abundant in Au-Ag deposits, where it is commonly found with Au-Ag minerals only rarely does it occur in Pb-Zn and Cu deposits. Albite is very rare and is reported only from the Nebazawa Au-Ag deposits. Barite is a common gangue constituent in Pb-Zn-Mn deposits, especially those in the southwestern part of Hokkaido and the northern part of Honshu, where it is usually a late-stage mineral coexisting with carbonate and quartz but rarely with sulfide minerals. Other rare gangue minerals include fluorite, apatite, gypsum, bementite, rutile, and sphene, but they have not been studied. 

Dominant gangue minerals are quartz, muscovite, chlorite, actinolite, hornblende, epidote, and biotite (Table 2.22). Minor minerals are rutile, illite, sphene, and glauco-phane. It is interesting to note that silicate minerals such as chlorite, epidote, pumpellyite, and albite are common and actinolite has been reported from the basalt near the Ainai Kuroko deposits (Shikazono et al., 1995) and they are also common in the basic schist which host the Motoyama Kuno deposits (Yui, 1983). 

The electrostatic separation method is the exclusive choice in some specific situations, for example in the cases of rutile and ilmenite deposits. These deposits generally contain minerals of similar specific gravities and similar surface properties so that processes such as flotation are unsuitable for concentration. The major application of electrostatic separation is in the processing of beach sands and alluvial deposits containing titanium minerals. Almost all the beach sand plants in the world use electrostatic separation to separate rutile and ilmenite from zircon and monazite. In this context the flowsheet given later (see Figure 2.35 A) may be referred to. Electrostatic separation is also used with regard to a number of other minerals. Some reported commercial separations include those of cassiterite from scheelite, wolframite from quartz, cassiterite from columbite, feldspar from quartz and mica, and diamond from heavy associated minerals. Electrostatic separation is also used in industrial waste recovery. 

Stishovite is a high-pressure modification of Si02 having the rutile structure. Should it have longer or shorter Si-O bond lengths than quartz ... 

Placer deposits, in general conglomerates, which contain quartz, sericite, chlorite, tourmaline and sometimes rutile and graphite. Gold can be coarse. Some deposits contain up to 3% pyrite. Size ofthe gold contained in pyrite ranges from O.Olto 0.07 pm... 

India has very large deposits of monazite on the coastal shores of Kerala and Chennai. A typical mineral composition of this type of deposit is 60% ilmenite, 1.2% rutile, 5% zircon, 6.4% garnet, 4% silinanite, 16% quartz, 2.5-5% monazite and 1-7% shell. Research work involved different anionic collectors and pH during monazite flotation, along with the level of sodium silicate used as depressant. 

Figure 11.30 Reduced partition function for various minerals calulated by Kieffer (1982) through equation 11.61 plotted against T. Heavy curve labeled H20(l) is reduced partition function of water according to Becker (1971). Dashed curve is a extrapolation of high-r reduced partition curve for quartz. Mineral abbreviations Qtz (quartz), Calc (calcite), Albt (albite), Muse (muscovite), Enst (clinoenstatite), Anor (anorthite). Diop (diopside), Pyrp (pyrope), Gros (grossular), Zron (zircon), Fors (forsterite), Andr (andra-dite), Rutl (rutile). Reprinted with permission from Kieffer (1982), Review of Geophysics and Space Physics, 20, 827-849, copyright 1982 by the American Geophysical Union.

The fault-fill mineralization includes quartz, dolomite, ankerite, siderite, calcite, molybdenite, pyrrhotite, arsenopyrite, pyrite, chalcopyrite, sphalerite, galena, selenian galena, marcasite, ilmenite, and rutile (Maanijou 2007). 

Microlithofacial classification of the sandstones is based on Dott s classification modified by Pettijohn et al. (1972). They are mostly arenites and subarkose and quartz wackes (rare sublithic, sporadically lithic and arkosic). Quartz is the main component of the sandstones (about 60-70 vol. percent). Feldspars (6 vol. percent) are mostly represented by potassium feldspars with plagioclases in lesser amounts. Some micas (muscovite and biotite) and chlorites are observed. Mica content of arenites reaches 3 vol. %, but is higher in the wackes. Heavy minerals present include zircon, sphene, rutile and apatite. Magmatic rocks (volcanic more than Plutonic) are predominant among lithoclasts (about 2 vol. %), but some metamorphic and sedimentary clasts being present too. 

Clear crystals of quartz, some of which are many inches in length, can contain embedded within them needles of the mineral rutile (Ti02) and of tourmaline. Such materials are referred to as rutilated or tourmalinated quartz (Dietrich, 1985). 

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