Optically transparent glass ceramic materials comprising a glass phase containing and a crystalline tungsten bronze phase comprising nanoparticles and having the formula M.sub.xWO.sub.3, where M includes at least one H, Li, Na, K, Rb, Cs, Ca, Sr, Ba, Zn, Cu, Ag, Sn, Cd, In, Tl, Pb, Bi, Th, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu, and U, and where 0<x<1. Aluminosilicate and zinc-bismuth-borate glasses comprising at least one of Sm.sub.2O.sub.3, Pr.sub.2O.sub.3, and Er.sub.2O.sub.3 are also provided.

Manufacturing glass ceramic materials comprises ceramming a glass to grow a crystalline tungsten bronze phase comprising nanoparticles having a formula M.sub.xWO.sub.3, where M includes a dopant cation, and where 0<x<1.

Provided are black crystallized glass that is safe and easy to produce, and reinforced crystallized glass of the black crystallized glass. Crystallized glass and reinforced crystallized glass containing, by wt % in terms of oxide, 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 components selected from a MgO component and a ZnO component, 0% to 3.0% of a CaO component, 1.0% to 3.5% of a TiO.sub.2 component, and 1.0% to 6.5% of a Fe.sub.2O.sub.3 component, and not containing a CoO component and a Co.sub.3O.sub.4 component.

The present invention relates to a chemically strengthened glass having a thickness of t (unit: .Math.m) and a relative permittivity of 7.0 or less at 20° C. and a frequency of 10 GHz, in which a value of Z determined by the following formula is 0.65 or more, where S1 is an entropy function calculated from an amount of alkali ions in a center portion of the glass, S2 is an entropy function calculated from an average amount of alkali ions from a glass surface to a depth of 0.05t, and X (unit: MPa) is an average value of a compressive stress in a region from the glass surface to the depth of 0.05t: Z = (S2 - S1) × 10 + X/1000.

A glass composition includes: greater than or equal to 53 mol % and less than or equal to 70 mol % SiO.sub.2; greater than or equal to 9 mol % and less than or equal to 20 mol % Al.sub.2O.sub.3; greater than or equal to 10 mol % and less than or equal to 17.5 mol % B.sub.2O.sub.3; greater than or equal to 0 mol % Li.sub.2O; greater than or equal to 0 mol % Na.sub.2O; and greater than 0.1 mol % of a nucleating agent. The sum of Li.sub.2O and Na.sub.2O in the glass composition may be greater than or equal to 8 mol % and less than or equal to 30 mol %. The amount of Al.sub.2O.sub.3 minus the sum of R.sub.2O and RO in the glass composition may be greater than or equal to −3 mol %. The glass composition may be phase separable and may have an improved K.sub.Ic fracture toughness.

Compounds, compositions, articles, devices, and methods for the manufacture of light guide plates and back light units including such light guide plates made from glass. In some embodiments, light guide plates (LGPs) are provided that have similar or superior optical properties to light guide plates made from PMMA and that have exceptional mechanical properties such as rigidity, CTE and dimensional stability in high moisture conditions as compared to PMMA light guide plates.

A black lithium silicate glass ceramic is provided. The glass ceramic includes lithium silicate as a primary crystal phase and at least one of petalite, β-quartz, β-spodumene, cristobalite, and lithium phosphate as a secondary crystal phase. The glass ceramic is characterized by the color coordinates: L*: 20.0 to 40.0, a*: −1.0 to 1.0, and b*: −5.0 to 2.0. The glass ceramic may be ion exchanged. Methods for producing the glass ceramic are also provided.

A glass ceramic substrate contains a glass ceramic having a compressive stress layer on a surface thereof and a crystalline phase containing LiAlSi.sub.4O.sub.10, quartz, and quartz solid solution. The glass ceramic has 60 to 80% of SiO.sub.2, 4 to 20% of Al.sub.2O.sub.3, more than 0 but less than or equal 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. The quartz and the quartz solid solution crystalline phase account for 15 to 30% of the glass ceramic by wt %, the LiAlSi.sub.4O.sub.10 crystalline phase accounts for not greater than 15% of the glass ceramic by wt %, and a ratio of ZrO.sub.2/Li.sub.2O is more than 0 but less than or equal to 0.35.

A microcrystalline glass product. The microcrystalline glass product includes the following components in percentage by weight: SiO.sub.2: 45-70%; Al.sub.2O.sub.3: 8-18%; Li.sub.2O: 10-25%; ZrO.sub.2: 5-15%; P.sub.2O.sub.5: 2-10%; and Y.sub.2O.sub.3: greater than 0 but less than or equal to 8%. Through reasonable component design, the microcrystalline glass and the microcrystalline glass product have excellent mechanical and optical properties and are suitable for electronic devices or display devices.

Provided is reinforced crystallized glass that has a high strength and is less likely to break. The reinforced crystallized glass includes a compressive stress layer on a surface, and [CS.sub.50 μm*(DOL.sub.zero−50)]/2 is 2000 or more, where CS.sub.50 μm (MPa) is a compressive stress at a depth of 50 μm from an outermost surface, and DOL.sub.zero (μm) is a stress depth when the compressive stress is 0 MPa.