Tourmalinated quartz

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). 

Actinolite, Chrysotile Stibnite Beryl, tourmaline Quartz, apatite... 

Dispersion staining is useful for rapid deterrnination of refractive index and dispersion. It is appHed most often, however, for needle-in-a-haystack detection of any particular substance in a mixture such as chrysotile in insulation, cocaine in dust samples, quartz in mine samples, or any particular mineral, eg, tourmaline, in a forensic soil sample. 

Strahl-keil, m. belemnite. -kies, m. marcasite. -kondensator, m. jet condenser, -korper, m. radiating body, radiator, -ptimpe, /. jet pump, injector, -punkt, m. radiating point, radiant point, -quarz, m. fibrous quartz, -schdrl, m. radiated tourmaline, -stein, m. actinolite amianthus. 

Tourmaline occurs in three bedrock samples in considerable amounts (up to 650 grains/sample) but in two of these samples, both from barren brecciated porphyry, tourmaline occurs as very small grains (<0.05 mm) intercalated with quartz so that few grains are heavier than 3.2 g/cm3 in the 0.25-0.5 mm fraction. The fragmental nature of the tourmaline grains in crackle breccias hampers the use of tourmaline as an indicator mineral for the NICO deposit. 

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... 

Disseminated deposits. In these deposits, the cassiterite grains range from 0.2 to 0.001mm. Cassiterite is mostly dispersed in gangue matrix of alumosilicates, tourmaline and quartz. Recovery of cassiterite from these deposits is quite difficult. 

Quartz Mica Feldspar Tourmaline Topaz Fe203 Garnet Tautalite... 

Wall rocks in the HMC deposit have 5 C values that range from -0.5 to -3.9 %o and values that range from 9.7 to 14.2 %o (Kerrich Hodder 1982). Quartz and carbonate in quartz-tourmaline-ankerite veins have values that range from 10.6 to 17.6 %o and 11.4 to 14.3 %o, respectively (Wood 1991). 

From the very beginning of their experiments, the Curie brothers realized that the linear piezoelectric effect only exists in anisotropic crystals, such as quartz, tourmaline, and Rochelle salt (Curie and Curie, 1880). In fact, as seen from Fig. 9.3, if the +z and -z directions of the plate are equivalent, by reversing the direction of the electric field E-s, the strain should be the same. In such cases, the strain should be proportional to Es 1 instead of E3. In other words, there should be no linear piezoelectric effect. 

The most commonly used pressure transducers are piezoelectric gages, commonly quartz or tourmaline. The output of these gages (usually as voltage-time plots) is recorded oscillographically. To convert the vertical deflections on the oscillo-... 

This ore is found in tho various localities already reforred to, accompanied with quartz, mica, fluorspar, apatite, topaz, tourmaline, wolfram, heavyspar, mispickel in the lode and in the alluvial bods of valleys and plains. 

The destruction of color centers (1,3) by heating can result in bleaching or fading. Examples are brown or blue topaz, red tourmaline, smoky quartz, and some yellow sapphire. In other instances there may be a color change as when amethyst turns into yellow citrine, or when the heating of a brown topaz reveals the presence of a previously hidden Cr-derived color in a pinked topaz. These changes can usually be reversed by an irradiation treatment. 

Statement 1. Bituminous sand is an aggregate of sand, clayey matter, oil and water. The sand consists mainly of quartz particles of 50 to 200-mesh size and smaller, but also of particles of other minerals including mica, rutile, ilmenite, tourmaline, zircon, spinel, garnet, pyrite, and lignite. Clay occurs interbedded with the bituminous sand itself. Ironstone nodules of all sizes up to eight inches in diameter occur in the bituminous sand beds, especially in the southern part of the deposit. The oil is viscous, naphthenic, and of a specific... 

China-clay rack is a kaolinized granite made up chiefly of quartz and kaolin, with sometimes tire presence of muscovite and tourmaline. The rock crumbles easily in the lingers. China stone is 11) a partially kaolinized granite, which contains quartz, kaolin, and sometimes mica and fluorite, is harder than china-clay rock and is used as a glaze in the production ol china or (2i a fine-grained, compact mudstone or limestone found in England and Wales... 

Pegmatites represent a residual phase of igneous depositions, characterized by extremely coarse crystalline material, that results Ironi the presence of associated volatiles, e.g.. water vapor, carbon dioxide, sulfur dioxide, and others, which decrease tile viscosity and facilitate crystallization. Quartz, feldspar, and mica are the more common minerals found in this environment. but Mich bodies are also hosts for many rare minerals and several types of gem stones, e.g.. beryl, tourmaline, and topaz. 

Quart/ and tourmaline erysials once were commercially important lor their piezoelectric properties as radio oscillation wafers and other electronic and instrumental uses. Synthesized quartz.crystals have largely replaced the need lor natural quartz for such applications... 

In addition to natural quartz. Rochelle salts, and tourmaline, synthetic crystals, such as ethylenediamine tartrate (EDT), dipotassium tartrate (DKT), and ammonium dihydrogen phosphate (ADPj have varying suitability as piezoelectric elements. While Rochelle salt has a greater piezoelectric effect than any other crystal, it has the disadvantage uf a greater sensitivity to temperature change than quartz. EDT has an advantage over quartz when used in frequency-modulated oscillators because of... 

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