Green colored glasses

Claim 1

A method for making a transparent green glass article containing crystallities in an amount of less than about 5% by volume, said crystallites consisting of nickel spinel, which consists of the steps of: a. melting a batch for a glass having an overall composition selected from the group: A. a glass consisting essentially, by weight on the oxide basis, of about 3-7.5% Li 2 O, 18-28% Al 2 O 3 , 58-72% SiO 2 , 0.3-4.5% NiO, 2.5-8% TiO 2 , and 0-3% ZrO 2 , the molar ratio of Al 2 O 3 to the sum of all modifier ions being at least 0.95; and B. a glass approximating the stoichiometry of carnegieite consisting essentially, by weight on the oxide basis, of about 10-20% Na 2 O, 30-35% Al 2 O 3 , 35-40% SiO 2 , 1-3% NiO, 4-8% TiO 2 , 0-10% K 2 O, and 0-3% ZrO 2 , the molar ratio of Al 2 O 3 to the sum of all modifier ions being at least 0.95; b. simultaneously cooling said melt to at least below the transformation range threof and shaping a transparent glass article therefrom; c. heating said transparent glass article to a temperature of at least about 675° C., but not more than about 900° C., for a period of time sufficient to cause the growth in situ of nickel spinel crystallites; and then d. cooling said crystallized article to room temperature, said article being transparent with a green coloration.

Claim 2

A method for making a transparent green glass article containing crystallities in an amount of less than about 5% by volume, said crystallites consisting of nickel spinel, which consists of the steps of: a. melting a batch for a glass having an overall composition selected from the group: A. a glass consisting essentially, by weight on the oxide basis, of about 3-7.5% Li 2 O, 18-28% Al 2 O 3 , 58-72% SiO 2 , 0.3-4.5% NiO, 2.5-8% TiO 2 , and 0-3% ZrO 2 , the molar ratio of Al 2 O 3 to the sum of all modifier ions being at least 0.95; and B. a glass approximating the stoichiometry of carnegieite consisting essentially, by weight on the oxide basis, of about 10-20% Na 2 O, 30-35% Al 2 O 3 , 35-40% SiO 2 , 1-3% NiO, 4-8% TiO 2 , 0-10% K 2 O, and 0-3% ZrO 2 , the molar ratio of Al 2 O 3 to the sum of all modifier ions being at least 0.95; b. simultaneously cooling said melt to at least below the transformation range threof and shaping a transparent glass article therefrom; c. heating said transparent glass article to a temperature of at least about 675° C., but not more than about 900° C., for a period of time sufficient to cause the growth in situ of nickel spinel crystallites; and then d. cooling said crystallized article to room temperature, said article being transparent with a green coloration.

Claim 7

A method for making a transparent green glass article containing crystallites in an amount of less than about 5% by volume, said crystallites consisting of nickel spinel, said article exhibiting a modulus of rupture of at least about 50,000 psi after being subjected to surface abrasion, and having an integral surface compression layer, which consists of the steps of: a. melting a batch for a glass having an overall composition selected from the group: A. a glass consisting essentially, by weight on the oxide basis, of about 3-7.5% Li 2 O, 18-28% Al 2 O 3 , 58-72% SiO 2 , 0.3-4.5% NiO, 2.5-8% TiO 2 , and 0-3% ZrO 2 , the molar ratio of Al 2 O 3 to the sum of all modifier ions being at least 0.95; and B. a glass approximating the stoichiometry of carnegieite consisting essentially, by weight on the oxide basis, of about 10-20% Na 2 O, 30-35% Al 2 O 3 , 35-40% SiO 2 , 1-3% NiO, 2, 4-8% TiO 2 0-10% K 2 O, and 0-3% ZrO 2 , the molar ratio of Al 2 O 3 to the sum of all modifier ions being at least 0.95; b. simultaneously cooling said melt to at least below the transformation range thereof and shaping a transparent glass article therefrom; c. heating said glass article to a temperature of at least about 675° C., but not more than about 900° C., for a period of time sufficient to cause the growth in situ of nickel spinel crystallites; d. subjecting said crystallized glass article, said article being transparent with a green coloration, to an ion exchange reaction selected from the group: I. contacting a surface of a transparent crystallized glass article made from a batch according to paragraph (A) above with an external source of Na + and/or K + ions at a temperature of at least 300° C., but below the strain point of the glass, for a period of time sufficient to cause an exchange of Na + and/or K + ions on a molar basis for Li + ions within the glass surface, this exchange causing the development of an integral surface compression layer on said transparent crystallized glass article; and Ii. contacting a surface of a transparent crystallized glass article made from a batch according to paragraph (B) above with an external source of K + ions at a temperature of at least 300° C., but below the strain point of the glass, for a period of time sufficient to cause an exchange of K + ions on a molar basis for Na + ions within the glass surface, this exchange causing the development of an integral surface compression layer on said transparent crystallized glass article.

Claim 8

A method for making a transparent green glass article containing crystallites in an amount of less than about 5% by volume, said crystallites consisting of nickel spinel, said article exhibiting a modulus of rupture of at least about 50,000 psi after being subjected to surface abrasion, and having an integral surface compression layer, which consists of the steps of: a. melting a batch for a glass having an overall composition selected from the group: A. a glass consisting essentially, by weight on the oxide basis, of about 3-7.5% Li 2 O, 18-28% Al 2 O 3 , 58-72% SiO 2 , 0.3-4.5% NiO, 2.5-8% TiO 2 , and 0-3% ZrO 2 , the molar ratio of Al 2 O 3 to the sum of all modifier ions being at least 0.95; and B. a glass approximating the stoichiometry of carnegieite consisting essentially, by weight on the oxide basis, of about 10-20% Na 2 O, 30-35% Al 2 O 3 , 35-40% SiO 2 , 1-3% NiO, 2, 4-8% TiO 2 0-10% K 2 O, and 0-3% ZrO 2 , the molar ratio of Al 2 O 3 to the sum of all modifier ions being at least 0.95; b. simultaneously cooling said melt to at least below the transformation range thereof and shaping a transparent glass article therefrom; c. heating said glass article to a temperature of at least about 675° C., but not more than about 900° C., for a period of time sufficient to cause the growth in situ of nickel spinel crystallites; d. subjecting said crystallized glass article, said article being transparent with a green coloration, to an ion exchange reaction selected from the group: I. contacting a surface of a transparent crystallized glass article made from a batch according to paragraph (A) above with an external source of Na + and/or K + ions at a temperature of at least 300° C., but below the strain point of the glass, for a period of time sufficient to cause an exchange of Na + and/or K + ions on a molar basis for Li + ions within the glass surface, this exchange causing the development of an integral surface compression layer on said transparent crystallized glass article; and Ii. contacting a surface of a transparent crystallized glass article made from a batch according to paragraph (B) above with an external source of K + ions at a temperature of at least 300° C., but below the strain point of the glass, for a period of time sufficient to cause an exchange of K + ions on a molar basis for Na + ions within the glass surface, this exchange causing the development of an integral surface compression layer on said transparent crystallized glass article.