A lithium silicate glass ceramic having lithium metasilicate as main crystal phase and having not more than 30 wt.-% of lithium metasilicate crystals and having the following components in the amounts indicated:

TABLE-US-00001 Component Wt.-% SiO.sub.2 71.0 to 82.0 Li.sub.2O 6.0 to 14.0 Me.sup.I.sub.2O 4.0 to 15.0 Al.sub.2O.sub.3 2.0 to 10.0 P.sub.2O.sub.5 0.5 to 7.0,
wherein Me.sup.I.sub.2O is selected from Na.sub.2O, K.sub.2O, Rb.sub.2O, Cs.sub.2O and mixtures thereof, and
wherein the molar ratio of SiO.sub.2 to Li.sub.2O is in the range of 2.5 to 5.0.

A lithium silicate glass ceramic having lithium metasilicate as main crystal phase and having not more than 30 wt.-% of lithium metasilicate crystals.

A glass composition comprises: 50.0 mol % to 70.0 mol % SiO.sub.2; 10.0 mol % to 25.0 mol % Al.sub.2O.sub.3; 0.0 mol % to 5.0 mol % P.sub.2O.sub.3; 0.0 mol % to 10.0 mol % B.sub.2O.sub.3; 5.0 mol % to 15.0 mol % Li.sub.2O; 1.0 mol % to 15.0 mol % Na.sub.2O; and 0.0 mol % to 1.0 mol % K.sub.2O. The sum of all alkali oxides, R.sub.2O, present in the glass composition may be in the range from greater than or equal to 11.0 mol % to less than or equal to 23.0 mol %. The sum of Al.sub.2O.sub.3 and R.sub.2O present in the glass composition may be in the range from greater than or equal to 26.0 mol % to less than or equal to 40.0 mol %. The glass composition may satisfy the relationship −0.1≤(Al.sub.2O.sub.3—(R.sub.2O+RO))/Li.sub.2O≤0.3.

Disclosed herein are glass compositions, articles made from the disclosed glass compositions, and methods of making the same. More specifically, disclosed herein is a glass composition comprising from about 10 to about 14 mol % of K.sub.2O; from 0 to about 4 mol % of CaO; from about 14 to about 18 mol % of Al.sub.2O.sub.3; and from about 66 to about 74 mol % SiO.sub.2.

A laminated glass article includes a glass core layer and a glass cladding layer adjacent to the glass core layer. At least one of the glass core layer or the glass cladding layer is a tinted layer. The tinted layer can include a tinting agent that imparts a color to the tinted layer.

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 to t, comprise a tangent with a slope having an absolute value greater than about 0.1 MPa/micrometer. 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 of less than about 71.5/√(t) (MPa). In some embodiments, the concentration of metal oxide or alkali metal oxide decreases from the first surface to a point between the first surface and the second surface and increases from the point 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.

In embodiments, a glass includes from 45 mol % to 70 mol % SiO.sub.2; from 11.5 mol % to 25 mol % Al.sub.2O.sub.3; from 2 mol % to 20 mol % Li.sub.2O; from greater than 0 mol % to 10 mol % Na.sub.2O; from 9 mol % to 19 mol % MgO; from 4 mol % ZrO.sub.2; and from 0 mol % to 0.5 mol % TiO.sub.2. In other embodiments, a glass includes from 45 mol % to 70 mol % SiO.sub.2; from 4 mol % to 25 mol % Al.sub.2O.sub.3; from 5 mol % to 20 mol % Li.sub.2O; from 0.1 mol % to 10 mol % Na.sub.2O; from 6 mol % to 25 mol % MgO; from 0.1 mol % to 4 mol % ZrO.sub.2; from 0.1 mol % to 5 mol % K.sub.2O; and from 0.05 mol % to 0.5 mol % SnO.sub.2.

A laminated glazing includes a first sheet of a colored glass and a second sheet of a clear glass which are joined together by a lamination interlayer, the first sheet having a thickness el ranging from 1.5 to 2.5 mm, the second sheet having a thickness e2 ranging from 0.4 to 1.9 mm, the ratio R=e2/e1.sup.2 being at most 0.40 mm.sup.−1, the glazing having a light transmission of at least 70% and a direct solar transmission of at most 55%, the colored glass having a chemical composition including a weight content of total iron, expressed in the form Fe.sub.2O.sub.3, ranging from 1.1 to 2.0%, with a redox ratio, defined as the ratio between the weight content of ferrous iron, expressed in the form FeO, and the weight content of total iron, expressed in the form Fe.sub.2O.sub.3, ranging from 0.23 to 0.32.

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. % Al.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.2O 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.

Chemically strengthened glass articles having at least one deep compressive layer extending from a surface of the article to a depth of at least about 45 μm within the article are provided. In one embodiment, the compressive stress profile includes a single linear segment extending from the surface to the depth of compression DOC. Alternatively, the compressive stress profile includes two linear portions: the first portion extending from the surface to a relatively shallow depth and having a steep slope; and a second portion extending from the shallow depth to the depth of compression. The strengthened glass has a 60% survival rate when dropped from a height of 80 cm in an inverted ball drop test and a peak load at failure of at least 10 kgf as determined by abraded ring-on-ring testing. Methods of achieving such stress profiles are also described.