Patent ID: 8263508

Claim:
A phosphosilicate glass ceramic comprising: a plurality of fluoroapatite crystals, wherein said fluoroapatite crystals have a maximum extension of less than 100 nm; a plurality of leucite crystals; and the following components in weight percent: SiO 2 57.6-62.0% Al 2 O 3 12.0-16.0% B 2 O 3 0.0-1.5% K 2 O 9.0-13.0% Na 2 O 5.0-8.0% Li 2 O 0.0-1.5% BaO 0.0-2.5% CaO 0.6-2.4% ZnO 0.0-3.0% TiO 2 0.0-1.5% ZrO 2 0.0-3.5% CeO 2 0.0-1.0% P 2 O 5 0.4-2.5% F 0.3-1.5%.