A luminescent particle including a surface comprising glass that surrounds one or more particles of one or more light emissive materials is disclosed. Preferably the surface comprises a vitrified glass. Methods form making a luminescent particle including a surface comprising glass that surrounds one or more particles of one or more light emissive materials is also disclosed. Compositions and products including a luminescent particle are further disclosed.

Methods for making articles comprising crystalline material. Exemplary articles made by a method described herein include electronics enclosure (e.g., a watch case, cellular phone case, or a tablet case).

Methods, systems and apparatus for producing continuous basalt fibers, microfibers, and microspheres from high temperature melts are disclosed. A cold crucible induction furnace is used to super heat crushed basalt rock to form a melt. The melt is cooled prior to forming a fiber. The fiber produced from the superheated melt possesses superior properties not found with conventional basalt fibers produced in gas furnaces. In some implementations, the superheated melt is spun into continuous basalt fibers. In some implementations, the superheated melt is blown into microfibers and microspheres.

A method of preparing a stable slurry of particles of glass precursors for spray drying and subsequent melting, such as by plasma melting, comprising grinding all constituent particles down to less than 50 microns in size, more desirably down to less than 25 or even less than 20 microns in size, removing the water from, or reducing the water content of the particles, mixing the particles with a liquid polymer binder and dispersant at a solids loading in the range of from 20-30%, more particularly in the range of from 22-27%, more desirably 24% by volume.

The present disclosure provides a retroreflective glass bead that includes at least one high refractive oxide selected from the group consisting of TiO.sub.2, BaO, La.sub.2O and Bi.sub.2O.sub.3; and at least one additive selected from the group consisting of MgO, CaO, ZnO, ZrO.sub.2, Al.sub.2O.sub.3, K.sub.2O, Na.sub.2O, Li.sub.2O and SrO. The glass bead according to the present invention have excellent retroreflectivity according to optical properties and excellent durability and productivity due to a simple structure, and also can be produced in various colors due to high chemical stability. Thus, the retroreflective aggregate including the glass bead according to the present invention exhibits very high visibility under various circumstances such as rainy or dry conditions. In addition, the method of producing a glass bead according to the present invention can reduce manufacturing costs while ensuring excellent productivity.

A luminescent particle including a surface comprising glass that surrounds one or more particles of one or more light emissive materials is disclosed. Preferably the surface comprises a vitrified glass. Methods form making a luminescent particle including a surface comprising glass that surrounds one or more particles of one or more light emissive materials is also disclosed. Compositions and products including a luminescent particle are further disclosed.