Patent ID: 7829490

Claim:
A glass composition suitable for fiber forming comprising: SiO 2 60-68 weight percent; B 2 O 3 7-12 weight percent; Al 2 O 3 9-15 weight percent; MgO 8-15 weight percent; CaO 0-4 weight percent; Li 2 O >0-2 weight percent; Na 2 O 0-1 weight percent; K 2 O 0-1 weight percent; Fe 2 O 3 0-1 weight percent; F 2 0-1 weight percent; TiO 2 0-2 weight percent; and other constituents 0-5 weight percent total. wherein the Li 2 O content is greater than either the Na 2 O content or the K 2 O content.