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.

Disclosed in the present invention is a beam coherence eliminating element. The optical medium material of the element comprises microcrystalline glass, wherein microcrystalline particles therein have a size of 0.1-1000 nm and are distributed randomly. As the crystals in the microcrystalline glass can change the phase of light beams, the microcrystalline glass can change the phase of the light beams randomly, thereby eliminating the coherence of the beams. The crystal size of the microcrystalline glass is small, and thus does not affect the transmission efficiency of light beams. The element of the present invention has a simple structure and is convenient to use, and can be added in the process of beam transmission to easily eliminate beam coherence.

Disclosed in the present invention is a beam coherence eliminating element. The optical medium material of the element comprises microcrystalline glass, wherein microcrystalline particles therein have a size of 0.1-1000 nm and are distributed randomly. As the crystals in the microcrystalline glass can change the phase of light beams, the microcrystalline glass can change the phase of the light beams randomly, thereby eliminating the coherence of the beams. The crystal size of the microcrystalline glass is small, and thus does not affect the transmission efficiency of light beams. The element of the present invention has a simple structure and is convenient to use, and can be added in the process of beam transmission to easily eliminate beam coherence.

Provided is a Li.sub.2O-Al.sub.2O.sub.3-SiO.sub.2-based crystallized glass that has a high permeability to light in a ultraviolet to infrared range and is less likely to be broken. A Li.sub.2O-Al.sub.2O.sub.3-SiO.sub.2-based crystallized glass contains, in terms of % by mass, 40 to 90% Si.sub.O2, 5 to 30% Al.sub.2O.sub.3, 1 to 10% Li.sub.2O, 0 to 20% SnO.sub.2, 0 to 5% ZrO.sub.2, 0 to 10% MgO, 0 to 10% P.sub.2O.sub.5, and 0 to 4% TiO.sub.2 and a mass ratio of Li.sub.2O/(MgO+CaO+SrO+BaO+Na.sub.2O+K.sub.2O) is 3 or less.

The present invention relates to a chemically strengthened glass ceramic including a crystalline phase, having two main surfaces opposed to each other, and including an amorphized region in a surface layer of at least one of the main surfaces and a crystallized region inside the glass, in which the amorphized region has a crystallinity of 10 vol % or less at a depth of 100 nm from an outermost surface of the glass.

The present invention relates to a chemically strengthened glass ceramic including a crystalline phase, having two main surfaces opposed to each other, and including an amorphized region in a surface layer of at least one of the main surfaces and a crystallized region inside the glass, in which the amorphized region has a crystallinity of 10 vol % or less at a depth of 100 nm from an outermost surface of the glass.

A glass-ceramic component is provided that has a low average coefficient of thermal expansion (CTE) and a high CTE homogeneity. The use of such a component and a process for producing such a component are also provided.

A glass-ceramic component is provided that has a low average coefficient of thermal expansion (CTE) and a high CTE homogeneity. The use of such a component and a process for producing such a component are also provided.

Methods for making articles comprising crystalline material. Exemplary articles made by a method described herein include electronics enclosure (e.g., a watch case, cellular phone case, or a tablet case).

Methods for making articles comprising crystalline material. Exemplary articles made by a method described herein include electronics enclosure (e.g., a watch case, cellular phone case, or a tablet case).