Abstract: A product having a transparent volume-coloured glass-ceramic is provided. The glass-ceramic includes, based on oxide, 58-72% by weight SiO2, 16-26% by weight Al2O3, 1.0-5.5% by weight Li2O, 2.0-<4.0% by weight TiO2, 0-<2.0 by weight ZnO, and 0.005-0.12% by weight MoO3, and where the glass-ceramic, based on a thickness of 4 mm, has a luminous transmittance ?vis of 0.5%-3.5%, and where the glass-ceramic has the property that after passage through the glass-ceramic, based on a thickness of 4 mm, light of the standard illuminant D65 has a colour locus in the white region A1 that in the CIExyY-2° chromaticity diagram is defined by the following coordinates: A1 0.3 0.27 0.28 0.315 0.35 0.38 0.342 0.31 0.3 0.27.

Abstract: The method of environmentally friendly melting and refining a glass melt of a crystallizable glass, which is used for making a lithium aluminum silicate (LAS) glass ceramic, includes the steps of providing a glass batch with a main batch composition within a lithium aluminum silicate (LAS) glass system, in which 0.1-<0.6% by weight of tin oxide has been added as main refining agent, but which does not contain arsenic oxide and/or antimony oxide as refining agent, formulating a raw material mixture for the glass batch, so that less than 40% by weight of the raw material mixture is quartz sand and then refining a glass melt formed from the glass batch at temperatures of at least 1600° C.

Abstract: The method of environmentally friendly melting and refining a glass melt of a crystallizable glass, which is used for making a lithium aluminium silicate (LAS) glass ceramic, includes the steps of providing a glass batch with a main batch composition within a lithium aluminium silicate (LAS) glass system, in which 0.1-<0.6% by weight of tin oxide has been added as main refining agent, but which does not contain arsenic oxide and/or antimony oxide as refining agent, formulating a raw material mixture for the glass batch, so that less than 40% by weight of the raw material mixture is quartz sand and then refining a glass melt formed from the glass batch at temperatures of at least 1600° C.

Abstract: In order to provide glass ceramic articles with an improved surface with regard to roughness, the invention relates to a method for producing glass ceramic panels (40) in which a green glass panel (10) is produced by hot forming and the green glass panel (10) is subsequently ceramized to form a glass ceramic, wherein the green glass panel (10) is fire-polished on at least one surface (11, 12) before or during the ceramizing.

Abstract: The translucent or opaque colored glass-ceramic article provides a cooking surface and has an adjustable light transmission in a visible range under 15%, as measured for a 4 mm sample thickness; a flaw-free upper surface with an impact resistance of greater than 18 cm breaking height, as tested with a 200 g steel ball in a falling ball test; a temperature difference resistance of greater than 500° C.; a high crystallinity with keatite mixed crystals as principal crystal phase in an interior of the glass-ceramic article and with a residual glass phase fraction of less than 8% by weight; a glassy upper surface layer of from 0.5 to 2.5 ?m thick, which is substantially free of high quartz mixed crystals and which inhibits chemical reactions, and a content of enriched ingredients in the residual glass phase in the interior of the glass-ceramic and in the glassy surface layer of ?Na2O+K2O+CaO+SrO+BaO+F+refining agents of from 0.2 to 1.6% by weight.