A glass-ceramic comprising, in weight percent on an oxide basis, of 50 to 70% SiO.sub.2, 0 to 20% Al.sub.2O.sub.3, 12 to 23% MgO, 0 to 4% Li.sub.2O, 0 to 10% Na.sub.2O, 0 to 10% K.sub.2O, 0 to 5% ZrO.sub.2, and 2 to 12% F, wherein the predominant crystalline phase of said glass-ceramic is a trisilicic mica, a tetrasilicic mica, or a mica solid solution between trisilicic and tetrasilicic, and wherein the total of Na.sub.2O+Li.sub.2O is at least 2 wt. %; wherein the glass-ceramic can be ion-exchanged.

The present invention relates to a spinel glass-ceramic made from a composition with the components 25 to 50% by weight SiO.sub.2, 10 to 35% by weight Al.sub.2O.sub.3, 1 to 15% by weight MgO, 1 to 15% by weight P.sub.2O.sub.5, 1 to 25% by weight ZrO.sub.2 and/or TiO.sub.2, 0 to 20% by weight La.sub.2O.sub.3, 0 to 10% by weight B.sub.2O.sub.3, and 0 to 15% by weight additives. The spinel glass-ceramic contains at least one spinel phase, but no high quartz solid solution phase. The glass-ceramic according to the invention exhibits very high mechanical stability, for example, very high flexural strength, wherein its optical properties can be simultaneously adjusted. In addition, the present invention also relates to a method for producing and the use of the spinel glass-ceramic. Furthermore, the present invention relates to a shaped dental product containing the spinel glass-ceramic.

Crystallized glass and strengthened crystallized glass with a novel composition, which have a high refractive index and high hardness, are provided. A crystallized glass, including, by mass % in terms of oxide, 20.0% or more and less than 40.0% of a SiO.sub.2 component, more than 0% and 20.0% or less of a Rn.sub.2O component, where Rn is one or more selected from Li, Na, and K, 7.0% to 25.0% of an Al.sub.2O.sub.3 component, 0% to 25.0% of a MgO component, 0% to 45.0% of a ZnO component, and 0% to 20.0% of a Ta.sub.2O.sub.5 component, in which a total amount of the MgO component, the ZnO component, and the Ta.sub.2O.sub.5 component is 10.0% or more.

A composition includes 30 mol % to 60 mol % SiO.sub.2; 15 mol % to 40 mol % Al.sub.2O.sub.3; 5 mol % to 25 mol % Y.sub.2O.sub.3; 5 mol % to 15 mol % TiO.sub.2; and 0.1 mol % to 15 mol % RO, such that RO is a sum of MgO, CaO, SrO, and BaO.

A tubular member for an exhaust gas treatment device according to at least one embodiment of the present invention includes: a tubular main body made of a metal; and an insulating layer formed at least on an inner peripheral surface of the tubular main body. The insulating layer contains glass containing a crystalline substance, and the glass contains silicon, boron, and magnesium.

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 glass ceramic seal is formed from a precursor material that includes from 80 mol % to 100 mol % of a primary component containing, on an oxide basis, from 25 mol % to 55 mol % SiO.sub.2, from 20 mol % to 45 mol % CaO, from 5 mol % to 30 mol % MgO, and from 0 mol % to 15 mol % Al.sub.2O.sub.3.

The present invention provides a red light emitting glass ceramic and a preparation method thereof, and an LED/LD light emitting device. A.sub.2Al.sub.4Si.sub.5O.sub.18:Eu.sup.2+ cordierite of the red light emitting glass ceramic capable of realizing blue light excited red light emission is a crystal phase material, wherein A is at least one of Mg, Ca, Sr, Ba and Zn and at least comprises Mg. The present invention particularly provides the red light emitting glass ceramic taking a chemical formula A.sub.2Al.sub.4Si.sub.5O.sub.18:Eu.sup.2+ as a crystal phase. The present invention further provides a preparation method of the transparent glass ceramic. The glass ceramic comprising the crystal phase, with the chemical formula of Mg.sub.2Al.sub.4Si.sub.5O.sub.18:Eu.sup.2+, is excited by blue light to emit red light, the internal/external quantum efficiencies reaching up to 94.5%/70.6%, respectively.

In one or more embodiments disclosed herein, an electronic device may include a display device operable to project an image, a front cover substrate positioned over the display device and including a transparent material, and a protective coating disposed on at least a portion of the non-display area of the front cover substrate. The front cover substrate may include a display area over the display device and a non-display area around at least the perimeter of the front cover substrate. The protective coating may include an inorganic material. The protective coating may not be positioned over the display area.

The present disclosure relates to fusion formable highly crystalline glass-ceramic articles whose composition lies within the SiO.sub.2—R.sub.2O.sub.3—Li.sub.2O/Na.sub.2O—TiO.sub.2 system and which contain a silicate crystalline phase comprised of lithium aluminosilicate (β-spodumene and/or β-quartz solid solution) lithium metasilicate and/or lithium disilicate. Additionally, these silicate-crystal containing glass-ceramics can exhibit varying Na.sub.2O to Li.sub.2O molar ratio extending from the surface to the bulk of the glass article, particularly a decreasing Li.sub.2O concentration and an increasing Na.sub.2O concentration from surface to bulk. According to a second embodiment, disclosed herein is a method for forming a silicate crystalline phase-containing glass ceramic.