Polychromatic glasses and method

Claim 1

In a transparent polychromatic glass article wherein a portion of the article contains microcrystals of alkali fluoride with at least one silver halide selected from the group consisting of silver chloride, silver bromide, and silver iodide in a concentration of at least 0.005% by volume, and wherein the same portion is integrally colored by metallic silver particles less than 200 A in the smallest dimension, the silver particles being deposited (a) as discrete colloidal particles, (b) within the microcrystals, and/or (c) on the surface of said microcrystals, the glass being characterized by the presence of ions of copper, samarium, terbium, praeseodymium, and/or europium in their higher oxidation state, and a portion of the article contains sodium fluoride, at least one silver halide selected from silver chloride, silver bromide, and silver iodide, and at least one sensitizing agent selected from the ions of copper, samarium, terbium, praeseodymium, and/or europium in their lower oxidation state.

Claim 8

A method of making a transparent polychromatic glass article, wherein a portion of the article is integrally colored by silver, consisting of, melting a glass batch containing the constituents of an alkali fluoride and at least one silver halide selected from the group consisting of silver chloride, silver bromide and silver iodide, and at least one sensitizing agent selected from the oxides of copper, samarium, terbium, praeseodymium, and europium, forming an article from such melt, wherein said sensitizing agent being present as ions in their lower oxidation state, exposing a portion of such article to ultraviolet radiation at ambient temperature, heating the exposed glass to a temperature between its transformation range and its softening point, for a sufficient length of time to cause growth of microcrystals of alkali fluoride with at least one silver halide selected from the group consisting of silver chloride, silver bromide and silver iodide, thereafter subjecting the article to a second ultraviolet radiation exposure and a second heat treatment to cause metallic silver particles less than 200 A in the smallest dimension to be deposited as discrete colloidal particles, or within or on the surface of the alkali fluoride microcrystals, and, cooling the article.

Claim 9

A method of making a transparent polychromatic glass article, wherein a portion of the article is integrally colored by silver, consisting of, melting a glass batch containing the constituents of an alkali fluoride and at least one silver halide selected from the group consisting of silver chloride, silver bromide and silver iodide, and at least one sensitizing agent selected from the oxides of copper, samarium, terbium, praeseodymium, and europium, forming an article from such melt, wherein said sensitizing agent being present as ions in their lower oxidation state, exposing a portion of such article to ultraviolet radiation at ambient temperature, heating the exposed glass to a temperature between its transformation range and its softening point, for a sufficient length of time to cause growth of microcrystals of alkali fluoride with at least one silver halide selected from the group consisting of silver chloride, silver bromide and silver iodide, thereafter subjecting the article to a second ultraviolet radiation exposure and a second heat treatment to cause metallic silver particles less than 200 A in the smallest dimension to be deposited as discrete colloidal particles, or within or on the surface of the alkali fluoride microcrystals, and, cooling the article.