Disclosed herein are glass-ceramics having crystalline phases including β-spodumene ss and either (i) pseudobrookite or (ii) vanadium or vanadium containing compounds so as to be colored and opaque glass-ceramics having coordinates, determined from total reflectance—specular included—measurements, in the CIELAB color space of the following ranges: L*=from about 20 to about 45; a*=from about −2 to about +2; and b*=from about −12 to about +1. Such CIELAB color space coordinates can be substantially uniform throughout the glass-ceramics. In each of the proceeding, β-quartz ss can be substantially absent from the crystalline phases. If present, β-quartz ss can be less than about 20 wt % or, alternatively, less than about 15 wt % of the crystalline phases. Also Further crystalline phases might include spinel ss (e.g., hercynite and/or gahnite-hercynite ss), rutile, magnesium zinc phosphate, or spinel ss (e.g., hercynite and/or gahnite-hercynite ss) and rutile.

Disclosed herein are glass-ceramics having crystalline phases including β-spodumene ss and either (i) pseudobrookite or (ii) vanadium or vanadium containing compounds so as to be colored and opaque glass-ceramics having coordinates, determined from total reflectance—specular included—measurements, in the CIELAB color space of the following ranges: L*=from about 20 to about 45; a*=from about −2 to about +2; and b*=from about −12 to about +1. Such CIELAB color space coordinates can be substantially uniform throughout the glass-ceramics. In each of the proceeding, β-quartz ss can be substantially absent from the crystalline phases. If present, β-quartz ss can be less than about 20 wt % or, alternatively, less than about 15 wt % of the crystalline phases. Also Further crystalline phases might include spinel ss (e.g., hercynite and/or gahnite-hercynite ss), rutile, magnesium zinc phosphate, or spinel ss (e.g., hercynite and/or gahnite-hercynite ss) and rutile.

Glass-ceramics and precursor glasses that are crystallizable to glass-ceramics are disclosed. The glass-ceramics of one or more embodiments include rutile, anatase, armalcolite or a combination thereof as the predominant crystalline phase. Such glasses and glass-ceramics may include compositions of, in mole %: SiO.sub.2 in the range from about 45 to about 75; Al.sub.2O.sub.3 in the range from about 4 to about 25; P.sub.2O.sub.5 in the range from about 0 to about 10; MgO in the range from about 0 to about 8; R.sub.2O in the range from about 0 to about 33; ZnO in the range from about 0 to about 8; ZrO.sub.2 in the range from about 0 to about 4; B.sub.2O.sub.3 in the range from about 0 to about 12, and one or more nucleating agents in the range from about 0.5 to about 12. In some glass-ceramic articles, the total crystalline phase includes up to 20% by weight of the glass-ceramic article.

Glass-ceramics and precursor glasses that are crystallizable to glass-ceramics are disclosed. The glass-ceramics of one or more embodiments include rutile, anatase, armalcolite or a combination thereof as the predominant crystalline phase. Such glasses and glass-ceramics may include compositions of, in mole %: SiO.sub.2 in the range from about 45 to about 75; Al.sub.2O.sub.3 in the range from about 4 to about 25; P.sub.2O.sub.5 in the range from about 0 to about 10; MgO in the range from about 0 to about 8; R.sub.2O in the range from about 0 to about 33; ZnO in the range from about 0 to about 8; ZrO.sub.2 in the range from about 0 to about 4; B.sub.2O.sub.3 in the range from about 0 to about 12, and one or more nucleating agents in the range from about 0.5 to about 12. In some glass-ceramic articles, the total crystalline phase includes up to 20% by weight of the glass-ceramic article.

A glass-ceramic, includes a silicate-containing glass comprising a first portion and a second portion. A plurality of crystalline precipitates comprising at least one of W and Mo. The crystalline precipitates are distributed within at least one of the first and second portions of the silicate-containing glass. The glass-ceramic comprises a difference in absorbance between the first and second portions of 0.04 optical density (OD)/mm or greater over a wavelength range of from 400 nm to 1500 nm.

A glass-ceramic, includes a silicate-containing glass comprising a first portion and a second portion. A plurality of crystalline precipitates comprising at least one of W and Mo. The crystalline precipitates are distributed within at least one of the first and second portions of the silicate-containing glass. The glass-ceramic comprises a difference in absorbance between the first and second portions of 0.04 optical density (OD)/mm or greater over a wavelength range of from 400 nm to 1500 nm.

A glass composition includes greater than or equal to 50 mol % and less than or equal to 70 mol % SiO.sub.2; greater than or equal to 10 mol % and less than or equal to 20 mol % Al.sub.2O.sub.3; greater than or equal to 1 mol % and less than or equal to 10 mol % B.sub.2O.sub.3; greater than or equal to 7 mol % and less than or equal to 14 mol % Li.sub.2O; greater than 0 mol % and less than or equal to 8 mol % Na.sub.2O; greater than 0 mol % and less than or equal to 1 mol % K.sub.2O; greater than or equal to 0 mol % and less than or equal to 7 mol % CaO; greater than or equal to 0 mol % and less than or equal to 8 mol % MgO; and greater than or equal to 0 mol % and less than or equal to 8 mol % ZnO. R.sub.2O+R′O is less than or equal to 25 mol %, wherein R.sub.2O is the sum of Li.sub.2O, Na.sub.2O, and K.sub.2O and R′O is the sum of CaO, MgO, and ZnO. The glass composition includes at least one of NiO+CO.sub.3O.sub.4+Cr.sub.2O.sub.3+CuO is greater than or equal to 0.001 mol %, CeO.sub.2 is greater than or equal to 0.1 mol %, and TiO.sub.2 is greater than or equal to 0.1 mol %.

A glass composition includes greater than or equal to 50 mol % and less than or equal to 70 mol % SiO.sub.2; greater than or equal to 10 mol % and less than or equal to 20 mol % Al.sub.2O.sub.3; greater than or equal to 1 mol % and less than or equal to 10 mol % B.sub.2O.sub.3; greater than or equal to 7 mol % and less than or equal to 14 mol % Li.sub.2O; greater than 0 mol % and less than or equal to 8 mol % Na.sub.2O; greater than 0 mol % and less than or equal to 1 mol % K.sub.2O; greater than or equal to 0 mol % and less than or equal to 7 mol % CaO; greater than or equal to 0 mol % and less than or equal to 8 mol % MgO; and greater than or equal to 0 mol % and less than or equal to 8 mol % ZnO. R.sub.2O+R′O is less than or equal to 25 mol %, wherein R.sub.2O is the sum of Li.sub.2O, Na.sub.2O, and K.sub.2O and R′O is the sum of CaO, MgO, and ZnO. The glass composition includes at least one of NiO+CO.sub.3O.sub.4+Cr.sub.2O.sub.3+CuO is greater than or equal to 0.001 mol %, CeO.sub.2 is greater than or equal to 0.1 mol %, and TiO.sub.2 is greater than or equal to 0.1 mol %.

According to at least one embodiment a glass comprises: a refractive index N of greater than 1.65 at a wavelength λ, where λ=587.6 nm; a glass density of not more than 4.2 g/cm.sup.3; Abbe number V.sub.d greater than 30; the glass comprising greater than 0.03 wt % of rare earth oxide with an atomic number of 58 or higher.

According to at least one embodiment a glass comprises: a refractive index N of greater than 1.65 at a wavelength λ, where λ=587.6 nm; a glass density of not more than 4.2 g/cm.sup.3; Abbe number V.sub.d greater than 30; the glass comprising greater than 0.03 wt % of rare earth oxide with an atomic number of 58 or higher.