| 摘要 |
There is provided an optical glass suitable for precision mold pressing having optical constants of a refractive index (nd) within a range from 1.75 to 1.85 and an Abbe number (nud) within a range from 35 to 45, comprising, said optical glass being free of Yb2O3, Y2O3 and TeO2, in mass % on the basis of the oxides: said optical glass having a transition point (Tg) within a range from 500° C. to 590° C. and a yield point (At) within a range from 530° C. to 630° C., and being free from devitrification in a devitrification test conducted under a condition of 950° C./2 hours.
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