A glass-ceramic includes a silicate-containing glass and crystals within the silicate-containing glass. The crystals include non-stoichiometric tungsten and/or molybdenum sub-oxides, and the crystals are intercalated with dopant cations.

A high-hardness transparent glass ceramic and a preparation method therefor, wherein the components by weight percentage include: 55.0%-70.0% of SiO.sub.2, 15.0%-20.0% of Al.sub.2O.sub.3, 0%-10.0% of MgO, and 0%-12.5% of ZnO, necessarily including one of MgO or ZnO, and the crystallized glass thereof contains microcrystals of spinel crystal. In the present invention, a suitable precursor glass is subjected to thermal treatment, and microcrystals are separated from the glass substrate by crystallization, producing a glass ceramic having a Moh's hardness greater than 7 and a visible-light transparency rate greater than 80% through 1 mm of the glass. The glass ceramic of the invention overcomes the problem that ordinary optical glass is easy to be scratched. The present glass ceramic can be served as protective face for mobile phones, protective glass for optical instruments and in communications equipment, substrate for magnetic disks, LCD panel, or protective glass for other optoelectronic devices.

An article that can include a glass including SiO.sub.2 from 25 mol % to 99 mol %, Al.sub.2O.sub.3 from 0 mol % to 50 mol %, WO.sub.3 plus MoO.sub.3 from 0.35 mol % to 30 mol %, and R.sub.2O from 0.1 mol % to 50 mol %. R.sub.2O is one or more of Li.sub.2O, Na.sub.2O, K.sub.2O, Rb.sub.2O and Cs.sub.2O. R.sub.2O minus Al.sub.2O.sub.3 is from 35 mol % to 7 mol %. The glass includes at least one of: (i) RO from 0.02 mol % to 50 mol % and (ii) SnO.sub.2 is from 0.01 mol % to 5 mol %. RO is one or more of MgO, CaO, SrO, BaO and ZnO. The article can also include a glass-ceramic with at least one and one crystalline phase comprising an oxide, from 0.1 mol % to 100 mol % of the crystalline phase, of at least one of: (i) W, (ii) Mo, (iii) V and an alkali metal cation, and (iv) Ti and an alkali metal cation.

A magnetizable glass ceramic composition including: a continuous first glass phase including SiO.sub.2, B.sub.2O.sub.3, P.sub.2O.sub.5, and R.sub.2O; a discontinuous second glass phase including at least one of SiO.sub.2, B.sub.2O.sub.3, P.sub.2O.sub.5, R.sub.2O, or mixtures thereof; and a discrete magnetizable crystalline phase dispersed in the discontinuous second glass phase, where R.sub.2O is selected from at least one of K.sub.2O, Li.sub.2O, Na.sub.2O, or mixtures thereof. Also disclosed are a method of making and a method of using the magnetizable glass ceramic composition.

Provided is a high-strength crystallized glass or substrate having a high visible light transmittance and a good color balance, which is suitable for use in protecting members of portable electronic devices, optical devices and the like. Provided is a crystallized glass comprising, in terms of mol % on an oxide basis: an SiO.sub.2 component of 30.0% or more and 70.0% or less, an Al.sub.2O.sub.3 component of 8.0% or more and 25.0%, an Na.sub.2O component of 0% or more and 25.0% or less, an MgO component of 0% or more and 25.0% or less, a ZnO component of 0% or more and 30.0% or less and a TiO.sub.2 component of 0% or more and 10.0% or less, the molar ratio [Al.sub.2O.sub.3/(MgO+ZnO)] having a value of 0.5 or more and 2.0 or less, and comprising one or more selected from RAl.sub.2O.sub.4, RTi.sub.2O.sub.5, R.sub.2TiO.sub.4, R.sub.2SiO.sub.4, RAl.sub.2Si.sub.2O.sub.8 and R.sub.2Al.sub.4Si.sub.5O.sub.18 as a crystal phase.

Embodiments of the present disclosure pertain to crystallizable glasses and glass-ceramics that exhibit a black color and are opaque. In one or more embodiments, the crystallizable glasses and glass-ceramics include a precursor glass composition that exhibits a liquidus viscosity of greater than about 20 kPa*s. The glass-ceramics exhibit less than about 20 wt % of one or more crystalline phases, which can include a plurality of crystallites in the Fe.sub.2O.sub.3TiO.sub.2MgO system and an area fraction of less than about 15%. Exemplary compositions used in the crystallizable glasses and glass-ceramics include, in mol %, SiO.sub.2 in the range from about 50 to about 76, Al.sub.2O.sub.3 in the range from about 4 to about 25, P.sub.2O.sub.5+B.sub.2O.sub.3 in the range from about 0 to about 14, R.sub.2O in the range from about 2 to about 20, one or more nucleating agents in the range from about 0 to about 5, and RO in the range from about 0 to about 20.

The invention relates to glass articles suitable for use as electronic device housing/cover glass which comprise a glass ceramic material. Particularly, a cover glass comprising an ion-exchanged glass ceramic exhibiting the following attributes (1) optical transparency, as defined by greater than 90% transmission at 400-750 nm; (2) a fracture toughness of greater than 0.6 MPa.Math.m.sup.1/2; (3) a 4-point bend strength of greater than 350 MPa; (4) a Vickers hardness of at least 450 kgf/mm.sup.2 and a Vickers median/radial crack initiation threshold of at least 5 kgf; (5) a Young's Modulus ranging between about 50 to 100 GPa; (6) a thermal conductivity of less than 2.0 W/m C., and (7) and at least one of the following attributes: (i) a compressive surface layer having a depth of layer (DOL) greater and a compressive stress greater than 400 MPa, or, (ii) a central tension of more than 20 MPa.

The invention relates to glass articles suitable for use as electronic device housing/cover glass which comprise a glass ceramic material. Particularly, a cover glass comprising an ion-exchanged glass ceramic exhibiting the following attributes (1) optical transparency, as defined by greater than 90% transmission at 400-750 nm; (2) a fracture toughness of greater than 0.6 MPa.Math.m.sup.1/2; (3) a 4-point bend strength of greater than 350 MPa; (4) a Vickers hardness of at least 450 kgf/mm.sup.2 and a Vickers median/radial crack initiation threshold of at least 5 kgf; (5) a Young's Modulus ranging between about 50 to 100 GPa; (6) a thermal conductivity of less than 2.0 W/m C., and (7) and at least one of the following attributes: (i) a compressive surface layer having a depth of layer (DOL) greater and a compressive stress greater than 400 MPa, or, (ii) a central tension of more than 20 MPa.