A glass-ceramic comprising, in weight percent on an oxide basis, of 50 to 70% SiO.sub.2, 0 to 20% Al.sub.2O.sub.3, 12 to 23% MgO, 0 to 4% Li.sub.2O, 0 to 10% Na.sub.2O, 0 to 10% K.sub.2O, 0 to 5% ZrO.sub.2, and 2 to 12% F, wherein the predominant crystalline phase of said glass-ceramic is a trisilicic mica, a tetrasilicic mica, or a mica solid solution between trisilicic and tetrasilicic, and wherein the total of Na.sub.2O+Li.sub.2O is at least 2 wt. %; wherein the glass-ceramic can be ion-exchanged.

A glass-ceramic comprising, in weight percent on an oxide basis, of 50 to 70% SiO.sub.2, 0 to 20% Al.sub.2O.sub.3, 12 to 23% MgO, 0 to 4% Li.sub.2O, 0 to 10% Na.sub.2O, 0 to 10% K.sub.2O, 0 to 5% ZrO.sub.2, and 2 to 12% F, wherein the predominant crystalline phase of said glass-ceramic is a trisilicic mica, a tetrasilicic mica, or a mica solid solution between trisilicic and tetrasilicic, and wherein the total of Na.sub.2O+Li.sub.2O is at least 2 wt. %; wherein the glass-ceramic can be ion-exchanged.

A manufacturing method of a glass substrate having holes includes irradiating a plurality of hole formation target positions of a dummy glass substrate with a laser under a first condition, to form a plurality of holes in the dummy glass substrate; heating the dummy glass substrate under a second condition; measuring, for each of the hole formation target positions, a deviation between the hole formation target position and a position of the hole after the heating formed by irradiating the hole formation target position of the dummy glass substrate; irradiating irradiation target positions of a glass substrate, having substantially same shape, dimension and composition as the dummy glass substrate, with a laser under the first condition, to form a plurality of holes, the irradiation target positions of the glass substrate with the laser being determined taking into account the deviation; and heating the glass substrate under the second condition.

A manufacturing method of a glass substrate having holes includes irradiating a plurality of hole formation target positions of a dummy glass substrate with a laser under a first condition, to form a plurality of holes in the dummy glass substrate; heating the dummy glass substrate under a second condition; measuring, for each of the hole formation target positions, a deviation between the hole formation target position and a position of the hole after the heating formed by irradiating the hole formation target position of the dummy glass substrate; irradiating irradiation target positions of a glass substrate, having substantially same shape, dimension and composition as the dummy glass substrate, with a laser under the first condition, to form a plurality of holes, the irradiation target positions of the glass substrate with the laser being determined taking into account the deviation; and heating the glass substrate under the second condition.

One aspect is a process to producing a synthetic quartz glass, including an annealing treatment that includes: putting a synthetic quartz glass as a parent material into a heat treatment furnace; elevating a temperature in the heat treatment furnace to a prescribed keeping temperature that is equal to or higher than the annealing point; keeping the keeping temperature; annealing the synthetic quartz glass; and taking the synthetic quartz glass out of the heat treatment furnace. The process includes determining an annealing rate v [° C./h] of the annealing step based on a value of S/V [mm.sup.2/mm.sup.3], wherein S [mm.sup.2] is the surface area of the synthetic quartz glass as a parent material and V [mm.sup.3] is the volume thereof and a target birefringence Re [nm/cm] for the synthetic quartz glass after the annealing, and the annealing step is performed at the determined annealing rate v.

One aspect is a process to producing a synthetic quartz glass, including an annealing treatment that includes: putting a synthetic quartz glass as a parent material into a heat treatment furnace; elevating a temperature in the heat treatment furnace to a prescribed keeping temperature that is equal to or higher than the annealing point; keeping the keeping temperature; annealing the synthetic quartz glass; and taking the synthetic quartz glass out of the heat treatment furnace. The process includes determining an annealing rate v [° C./h] of the annealing step based on a value of S/V [mm.sup.2/mm.sup.3], wherein S [mm.sup.2] is the surface area of the synthetic quartz glass as a parent material and V [mm.sup.3] is the volume thereof and a target birefringence Re [nm/cm] for the synthetic quartz glass after the annealing, and the annealing step is performed at the determined annealing rate v.

Systems and methods for displaying art in a manner which resists tipping from external forces while preserving artistic impression are disclosed. An art piece includes an inner core extending from a bottom of a display portion and an outer stabilizing core formed about the inner core. A base includes a recess located within a housing. The recess is configured to snugly receive the stabilizing core. A number of illumination devices are located within the recess and electrically connected to a power supply for illuminating the art piece. In some embodiments, holes may be formed in the base for fastening the base to a surface.

Systems and methods for displaying art in a manner which resists tipping from external forces while preserving artistic impression are disclosed. An art piece includes an inner core extending from a bottom of a display portion and an outer stabilizing core formed about the inner core. A base includes a recess located within a housing. The recess is configured to snugly receive the stabilizing core. A number of illumination devices are located within the recess and electrically connected to a power supply for illuminating the art piece. In some embodiments, holes may be formed in the base for fastening the base to a surface.

The present invention discloses an aluminosilicate glass composition, aluminosilicate glass and a preparation method therefor and application thereof. Based on the total molar weight of the aluminosilicate glass composition, the aluminosilicate glass composition comprises, by oxide, 67-74 mol % of SiO2, 10-15 mol % of Al2O3, 0-5 mol % of B2O3, 1-10 mol % of MgO, 1-10 mol % of CaO, 0-3 mol % of SrO, 2-8 mol % of BaO, 0.1-4 mol % of ZnO, 0.1-4 mol % of RE2O3 and less than 0.05 mol % of R2O, wherein RE represents rare earth elements, and R represents alkali metals.

The present invention discloses an aluminosilicate glass composition, aluminosilicate glass and a preparation method therefor and application thereof. Based on the total molar weight of the aluminosilicate glass composition, the aluminosilicate glass composition comprises, by oxide, 67-74 mol % of SiO2, 10-15 mol % of Al2O3, 0-5 mol % of B2O3, 1-10 mol % of MgO, 1-10 mol % of CaO, 0-3 mol % of SrO, 2-8 mol % of BaO, 0.1-4 mol % of ZnO, 0.1-4 mol % of RE2O3 and less than 0.05 mol % of R2O, wherein RE represents rare earth elements, and R represents alkali metals.