A glass-ceramic article comprises a petalite crystalline phase and a lithium silicate crystalline phase. The weight percentage of each of the petalite crystalline phase and the lithium silicate crystalline phase in the glass-ceramic article are greater than each of the weight percentages of other crystalline phases present in the glass-ceramic article. The glass-ceramic article has a transmittance color coordinate in the CIELAB color space of: L*=from 20 to 90; a*=from −20 to 40; and b*=from −60 to 60 for a CIE illuminant F02 under SCI UVC conditions. In some embodiments, the colorant is selected from the group consisting of TiO.sub.2, Fe.sub.2O.sub.3, NiO, Co.sub.3O.sub.4, MnO.sub.2, Cr.sub.2O.sub.3, CuO, Au, Ag, and V.sub.2O.sub.5.

Thin glass elements with improved edge strength are provided—from a sheet glass element that has two opposite parallel faces and an edge connecting the faces. The sheet glass element has a thickness of at most 700 μm. At least a portion of the edge is defined by an edge surface portion that is convexly curved, so that at least one of the faces merges into the edge surface portion, wherein a curved arc of the edge surface portion has a length that is at least 1/30 of the thickness of the sheet glass element. In the region of the convex curvature, the edge surface portion has indentations in the form of furrows.

Disclosed herein are glass-ceramics having crystalline phases including β-spodumene ss and either (i) pseudobrookite or (ii) vanadium or vanadium containing compounds so as to be colored and opaque glass-ceramics having coordinates, determined from total reflectance—specular included—measurements, in the CIELAB color space of the following ranges: L*=from about 20 to about 45; a*=from about −2 to about +2; and b*=from about −12 to about +1. Such CIELAB color space coordinates can be substantially uniform throughout the glass-ceramics. In each of the proceeding, β-quartz ss can be substantially absent from the crystalline phases. If present, β-quartz ss can be less than about 20 wt % or, alternatively, less than about 15 wt % of the crystalline phases. Also Further crystalline phases might include spinel ss (e.g., hercynite and/or gahnite-hercynite ss), rutile, magnesium zinc phosphate, or spinel ss (e.g., hercynite and/or gahnite-hercynite ss) and rutile.

Embodiments of a glass-based article including a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 millimeters or less (e.g., about 1 millimeter or less), and a stress profile, wherein all points of the stress profile between a thickness range from about 0.Math.t up to 0.3.Math.t and from greater than about 0.7.Math.t up to t, comprise a tangent with a slope having an absolute value greater than about 0.1 MPa/micrometer, are disclosed. In some embodiments, the glass-based article includes a non-zero metal oxide concentration that varies along at least a portion of the thickness (e.g., 0.Math.t to about 0.3.Math.t) and a maximum central tension in the range from about 80 MPa to about 100 MPa. In some embodiments, the concentration of metal oxide or alkali metal oxide decreases from the first surface to a value at a point between the first surface and the second surface and increases from the value to the second surface. The concentration of the metal oxide may be about 0.05 mol % or greater or about 0.5 mol % or greater throughout the thickness. Methods for forming such glass-based articles are also disclosed.

A glass ceramic contains the following components by wt %: 60 to 80% of SiO.sub.2; 4 to 20% of Al.sub.2O.sub.3; 0 to 15% of Li.sub.2O; more than 0 but less than or equal to 12% of Na.sub.2O; 0 to 5% of K.sub.2O; more than 0 but less than or equal to 5% of ZrO.sub.2; 0 to 5% of P.sub.2O.sub.5; and 0 to 10% of TiO.sub.2. A crystalline phase contains at least one of R.sub.2SiO.sub.3, R.sub.2Si.sub.2O.sub.5, R.sub.2TiO.sub.3, R.sub.4Ti.sub.5O.sub.12, R.sub.3PO.sub.3, RAlSi.sub.2O.sub.6, RAlSiO.sub.4O.sub.10, R.sub.2Al.sub.2Si.sub.2O.sub.5, R.sub.4Al.sub.4Si.sub.5O.sub.18, quartz and quartz solid solution. With a liquidus temperature below 1,450° C., a thermal conductivity above 2 w/m.Math.k, and a Vickers hardness above 600 kgf/mm2, the glass ceramic is applicable to portable electronic devices and optical devices.

Lithium silicate glass ceramics and glasses containing specific oxides of divalent elements are described which crystallize at low temperatures and are suitable in particular as dental materials.

The present invention relates to a method of fabricating an improved lithium silicate glass ceramic and to that material for the manufacture of blocks for dental appliances using a CAD/CAM process and hot pressing system. The lithium silicate material has a chemical composition that is different from those reported in the prior art with 1 to 10% of germanium dioxide in final composition. The softening points are close to the crystallization final temperature of 800° C. indicating that the samples will support the temperature process without shape deformation.

A method of manufacturing a lithium ion conductive solid electrolyte includes (a) a step of preparing an object to be processed including a crystalline material, that includes alkali metal other than lithium and whose ionic conductivity at room temperature is greater than or equal to 1×10.sup.−13 S/cm; and (b) a step of performing an ion-exchange process on the object to be processed in molten salt including lithium ions.

According to one embodiment, a glass-ceramic composition may include from about 60 mol. % to about 75 mol. % SiO.sub.2; from about 5 mol. % to about 10 mol. % AI.sub.2O.sub.3; from about 2 mol. % to about 20 mol. % alkali oxide R.sub.2O, the alkali oxide R.sub.2O including Li.sub.20 and Na.sub.2O; and from 0 mol. % to about 5 mol. % alkaline earth oxide RO, the alkaline earth oxide RO including MgO. A ratio of Al.sub.2O.sub.3 (mol. %)) to the sum of (R.sub.2O (mol. %)+RO (mol. %)) may be less than 1 in the glass-ceramic composition. A major crystalline phase of the glass-ceramic composition may be Li.sub.2Si.sub.2O.sub.5. A liquidus viscosity of the glass-ceramic composition may be greater than 35 kP. The glass-ceramic composition may be used to form the glass clad layer(s) of a laminated glass article.

The invention relates to a blank for producing a dental molded part such as an inlay, onlay, crown or bridge, and to a method for producing the blank. To be able to machine a dental molded part, in particular one having thin wall thicknesses, from the blank without difficulty, the blank is designed to consist of a glass ceramic having a density of between 30 and 60% of theoretical density, and of glass-ceramic powder particles with a particle size distribution d.sub.90≦80 μm, lithium silicate crystals being present in an amount of 10 to 90% by volume.