The present invention provides crystallized glass of three-dimensional shape for easily producing chemically strengthened glass of three-dimensional shape that resists damage and has exceptional transparency. This crystallized glass of three-dimensional shape: contains crystals; has light transmittance in terms of a thickness of 0.8 mm of 80% or higher; and contains 45-74% SiO.sub.2, 1-30% Al.sub.2O.sub.3, 1-25% Li.sub.2O, 0-10% Na.sub.2O, 0-5% K.sub.2O, a total of 0-15% of SnO.sub.2 and/or ZrO.sub.2, and 0-12% P.sub.2O.sub.5, these amounts expressing the oxide-based mass percentage.

The purpose of the present invention is to provide a chemically strengthened glass having excellent transparency and strength and being scratch resistant. The present invention pertains to a chemically strengthened glass that: has a compressive stress layer on the surface thereof; has a visible light transmittance of at least 70% when the thickness thereof is converted to 0.8 mm; has a surface compressive stress of at least 600 MPa; has a compressive stress depth of at least 80 m; and contains a -spodumene.

A glass comprising greater or equal to 30.0 mol % SiO.sub.2, the glass being free of iron, lead, antimony ant tantalum oxides, and having a refractive index n.sub.d greater than or equal to 1.75 and a linear thermal expansion coefficient .sub.20-300, in the temperature range 20-300 C., that is less than or equal to about 6510.sup.7 K.sup.1.

The present invention pertains to a glass for strengthening, that: has an average transmittance of at least 70% when converted to a thickness of 0.8 mm at a wavelength of 380-780 nm; has a haze value of no more than 0.7% when converted to a thickness of 0.8 mm in a C light source; has a Young's modulus of at least 85 GPa; has a fracture toughness value of at least 0.90 MPa.Math.m.sup.1/2; a thermal conductivity at 20 C. of at least 1.3 W/m.Math.K; and comprises a lithium aluminosilicate crystallized glass.

The invention relates to faceted gemstones based on a luminescent glass composition that contains particular oxides of rare earth metals and thus enables the faceted gemstones to be identified, and to a process for identifying the gemstones.

Glass ceramic material for the production of synthetic stones in fashion jewellery and jewellery, having excellent mechanical properties, chemical and heat resistance, harmless due to absence of lead, arsenic and cadmium compounds, available in a broad scale of colour designs, imitating faithfully natural precious stones thanks to high content of spinel crystalline phase and lowered content of SiO.sub.2, consisting of (in weight %): 20-40% SiO.sub.2, 1.5-10% B.sub.2O.sub.3, 20-35% Al.sub.2O.sub.3, 0.1-20% MgO, 0.1-20% ZnO, the content of MgO+ZnO being at least 10%, preferably also 0-15% TiO.sub.2, 0.1-15% ZrO.sub.2, the content of TiO.sub.2+ZrO.sub.2 being at least 5%, more preferably also 0-20% of colouring additives in the form of CoO, NiO, CuO, Fe.sub.2O.sub.3, MnO.sub.2, Cr.sub.2O.sub.3, V.sub.2O.sub.5, Pr.sub.2O.sub.3, CeO.sub.2, Nd.sub.2O.sub.3, Er.sub.2O.sub.3, AgO and Au.

Disclosed are a miserite crystallized glass for an artificial tooth and a method for coloring same, the method enabling a production of a uniform shade without degrading the physical properties of a crystallized glass by means of simply adding a small amount of coloring additive powder when preparing the crystallized glass. A miserite crystallized glass for an artificial tooth according to the present invention is colored with any one of the shades in groups A, B, C and D of the Vita shade guide which is a tooth shade reference. The miserite crystallized glass has a miserite crystal phase as the main phase and comprises a hydroxyapatite crystal phase and a xonotlite crystal phase as additional phases.

A refractive index device and method of making it include obtaining a glass structure comprising a plurality of nucleation sites. The glass structure is formed from a glass composition that comprises a first chemical component and a second chemical component. A crystal of the second chemical component has a different second refractive index from a first refractive index of the first chemical component. Each nucleation site defines where a crystal of the second chemical component can be grown. The method includes causing crystals of the second chemical component to grow in situ at a set of the plurality of nucleation sites in order to produce a spatial gradient of a refractive index in the glass structure.

A glass comprising greater or equal to 30.0 mol % SiO.sub.2, the glass being free of iron, lead, antimony ant tantalum oxides, and having a refractive index n.sub.d greater than or equal to 1.75 and a linear thermal expansion coefficient .sub.20-300, in the temperature range 20-300 C., that is less than or equal to about 6510.sup.7 K.sup.1.

The present invention relates to conductive pastes, suitable for use in solar cells, a method for the manufacture of a light receiving surface electrode of a solar cell, a light receiving electrode for a solar cell and a solar cell. The paste comprises a solids portion dispersed in an organic medium, the solids portion comprising electrically conductive metal, and mixed oxide, wherein the mixed oxide is a tellurium-bismuth-cerium mixed oxide and is substantially lead-free and substantially silicon-free.