Optical glass, prefabricated member and optical element

The optical glass is obtained at a lower price, the refractive index (nd) and the Abbe number (vd) of the optical glass are both within required ranges, and the stability is relatively high. The optical glass contains 44.0% or more and less than 55.0% of a B2O3 component and 7.0% or more and less than 11.0% of an Ln2O3 component, in the formula, Ln is one or more selected from the group consisting of La, Gd, Y and Yb, more than 7.0% and less than 12.5% of an SiO2 component, more than 7.0% and less than 13.0% of a Li2O component, more than 1.0% and less than 5.0% of a ZrO2 component, less than 1.0% of a Ta2O5 component, and less than 1.0% of a B2O3 component. The sum of moles (ZnO + Li2O) on an oxide basis is greater than 25.0% and 40.0% or less, and has a refractive index (nd) of 1.60-1.80, and an Abbe number (vd) of 40-60. 本发明以更低廉的价格获得一种光学玻璃，所述光学玻璃的折射率(nd)以及阿贝数(vd)均在所要求的范围内，并且稳定性较高。所述光学玻璃，以氧化物基准的摩尔计算，含有B2O3成分44.0％以上小于55.0％，Ln2O3成分7.0％以上小于11.0％，式中，Ln为从由La、Gd、Y、Yb组成的群中所选择的1种以上，SiO2成分为大于7.0％且12.5％以下，Li2O成分为大于7.