Embodiments of a transparent glass-based material comprising a glass phase and a second phase that is different from and is dispersed in the glass phase are provided. The second phase may comprise a crystalline or a nanocrystalline phase, a fiber, and/or glass particles. In some embodiments, the second phase is crystalline. In one or more embodiments, the glass-based material has a transmittance of at least about 88% over a visible spectrum ranging from about 400 nm to about 700 nm and a fracture toughness of at least about 0.9 MPa.Math.m.sup.1/2, and wherein a surface of the glass-based material, when scratched with a Knoop diamond at a load of at least 5 N to form a scratch having a width w, is free of chips having a size of greater than 3w.

A glass ceramic sintered body having a small dielectric loss in a high frequency band of 10 GHz or higher and stable characteristics against temperature variation and a wiring substrate using the same are provided. The glass ceramic sintered body contains crystallized glass, an alumina filler, silica, and strontium titanate. The content of the crystallized glass is 50 mass % to 80 mass %, the content of the alumina filler is 15.6 mass % to 31.2 mass % in terms of Al.sub.2O.sub.3, the content of silica is 0.4 mass % to 4.8 mass % in terms of SiO.sub.2, and the content of the strontium titanate is 4 mass % to 14 mass % in terms of SrTiO.sub.3.

An apparatus for holding glassware during processing includes a plurality of ware keepers, each ware keeper configured to receive a piece of glassware during the processing. Each ware keeper comprises a glass contact surface comprising a silicate material having a Knoop hardness less than or equal to 400 HK.sub.200 and a specific gravity greater than or equal to 1.5 and less than or equal to 6.

Aluminosilicate microcrystalline glass, and a manufacturing method and a product thereof, where in addition to a glass phase, the aluminosilicate microcrystalline glass includes principal crystalline phases: a magnesium aluminate (MgAl.sub.2O.sub.4) crystal including a volume percentage of 5% to 30%, a lithium disilicate (Li.sub.2Si.sub.2O.sub.5) crystal including a volume percentage of 10% to 30%, and a quartz and quartz solid solution including a volume percentage of 5% to 30%. Residues are other inevitable impurities. The inevitable impurities include intermediate products generated when the MgAl.sub.2O.sub.4 crystal, the Li.sub.2Si.sub.2O.sub.5 crystal, or the quartz and quartz solid solution is being generated, other impurities that are inevitable in a glass production process, and the like.

To provide a crystallized glass substrate including a surface with a compressive stress layer, in which a stress depth DOL.sub.zero of the compressive stress layer, at which the compressive stress is 0 MPa, is 45 to 200 μm, a compressive stress CS on an outermost surface of the compressive stress layer is 400 to 1400 MPa, and CS×DOL.sub.zero, which is a product of the compressive stress CS on the outermost surface and the stress depth DOL.sub.zero(μm), is 4.8×10.sup.4 or more.

A crystallized glass includes a crystallized glass mother material, and, in a surface, a compressive stress layer, wherein the crystallized glass has, for a thickness of 10 mm, a light transmittance of, including reflection loss, 80% at a wavelength in 400 to 669 nm, and has a Vickers hardness [Hv] of 835 to 1300. In the crystallized glass, the crystallized glass mother material contains, in % by weight on an oxide basis, 40.0% to 70.0% of a SiO.sub.2 component, 11.0% to 25.0% of an Al.sub.2O.sub.3 component, 5.0% to 19.0% of a Na.sub.2O component, 0% to 9.0% of a K.sub.2O component, 1.0% to 18.0% of a MgO component, 0% to 3.0% of a CaO component, and 0.5% to 12.0% of a TiO.sub.2 component, and a total content of the SiO.sub.2 component, the Al.sub.2O.sub.3 component, the Na.sub.2O component, the K.sub.2O component, the MgO component, and the TiO.sub.2 component is 90% or more.

To provide a crystallized glass substrate that is hard and resistant to fracture and that is also resistant to shattering upon breakage. A crystallized glass substrate includes a crystallized glass serving as a base material and a compressive stress layer forming a surface thereof. The crystallized glass contains, in % by weight on an oxide basis, 40.0% to 70.0% of a SiO.sub.2 component, 11.0% to 25.0% of an Al.sub.2O.sub.3 component, 5.0% to 19.0% of a Na.sub.2O component, 0% to 9.0% of a K.sub.2O component, 1.0% to 18.0% of one or more selected from a MgO component and a ZnO component, 0% to 3.0% of a CaO component, and 0.5% to 12.0% of a TiO.sub.2 component. The SiO.sub.2 component, the Al.sub.2O.sub.3 component, the Na.sub.2O component, the one or more selected from the MgO component and the ZnO component, and the TiO.sub.2 component are present in a total amount of 90% or more. The compressive stress layer has a depth of layer of 40 μm or more. The compressive stress layer has a surface compressive stress of 750 MPa or more. The compressive stress layer has a central tension of 65 MPa or less as determined by curve analysis.

Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools and which subsequently can be converted into lithium silicate products showing high strength.

Quartz solid solution glass ceramics and precursors thereof are described, which are characterized by very good mechanical and optical properties and in particular can be used as restoration material in dentistry.

A fitout article or article of equipment for a kitchen or laboratory is provided. The article has a lighting and separating element. The separating element in a region of the lighting element has light transmittance of at least 0.1% and less than 12%. The lighting element in the interior emits light that passes through the separating element and to the exterior. The separating element has a glass or glass-ceramic substrate having a CTE of −6 to 6 ppm/K and has a colour locus in the CIELAB colour space with the coordinates L* of 20 to 40, a* of −6 to 6 and b* of −6 to 6. D65 standard illuminant light, after passing through the separating element, is within a white region W1 determined in the chromaticity diagram CIExyY−2° by the following coordinates:

TABLE-US-00001 White region W1 x y 0.27 0.21 0.22 0.25 0.32 0.37 0.45 0.45 0.47 0.34 0.36  0.29.