China
Africa
Explore chapters and articles related to this topic
Direct, Discharge and Resist Styles of Printing
Published in Asim Kumar Roy Choudhury, Principles of Textile Printing, 2023
Luster is a gentle sheen or soft glow, resulting from a substance that is partly transparent and with a partly reflective surface. The reflective property of minerals with vitreous luster is similar to that of glass. This is a very common type of luster and can occur in minerals that are transparent or translucent, such as quartz and cal-cite. The glitter or sparkle effect of some pearlescent pigments is its ability to shine by reflection with many small flashes of brilliant light. For this purpose, titanium coated with mica powder is used (Ivana et al., 2018).
Minerals
Published in Dexter Perkins, Kevin R. Henke, Adam C. Simon, Lance D. Yarbrough, Earth Materials, 2019
Dexter Perkins, Kevin R. Henke, Adam C. Simon, Lance D. Yarbrough
Luster refers to the sheen of a mineral, that is, to the way it reflects light; some examples are shown in Figure 3.36. For example, minerals that have the shiny appearance of polished metal are said to have a metallic luster. Most minerals, however, do not have a metallic luster; they have a nonmetallic luster. Mineralogists use many terms to describe nonmetallic minerals. We call those that appear only partially metallic submetallic. Vitreous minerals, like quartz, have a glassy appearance. Adamantine minerals sparkle or appear brilliant like diamonds. Some not-so-spectacular minerals do not have bright or flashy lusters; we may describe them as earthy, dull, or resinous. Some mineral specimens, such as the sphalerite shown in Figure 3.36, may have more than one luster or color depending on how they were formed. Table 3.7 lists some of the more common terms used to describe luster.
Minerals
Published in F.G.H. Blyth, M. H. de Freitas, A Geology for Engineers, 2017
F.G.H. Blyth, M. H. de Freitas
Lustre is the appearance of a mineral surface in reflected light. It may be described as metallic, as in pyrite or galena; glassy or vitreous, as in quartz; resinous or greasy, as in opal; pearly, as in talc; or silky, as in fibrous minerals such as asbestos and satin-spar (fibrous gypsum). Minerals with no lustre are described as dull.
Geometallurgical characterisation of Mn ores
Published in Applied Earth Science, 2021
Michael John Peterson, James Robert Manuel, Sarath Hapugoda
In addition, generally fewer gangue groups would be required for most tetravalent Mn-dominated ores, perhaps a maximum of three to represent Fe-bearing, SiO2-bearing and alumina/aluminosilicate-bearing particles to account for common minor element impurities in tetravalent Mn oxide ores (Table 6). In supergene Mn ores where vitreous goethite (hard brown dense goethite, sometimes exhibiting a vitreous or glassy lustre, ochreous goethite (friable, highly microporous, ochre-coloured goethite) and hydrohaematite are present, it will probably not be practical to set up separate ore groups to separately account for each mineral/mineral form without burdening the scheme with too many extra categories. The distinction of these Fe oxyhydroxides is important for downstream processing in Fe ores (e.g. Donskoi et al. 2014).