Mold used for molding glass optical elements process for preparation of glass optical elements and method for rebirth of mold

A method of manufacturing glass optical elements by press molding a glass molding material with a press molding apparatus comprising upper and lower molds, comprising:

• preparing the upper and lower molds;
• repeating a process of press molding the glass molding material with the upper and lower molds;
• reproducing at least one molding surface of the upper or lower mold, when the molding surface is impaired due to the repetition of the molding;
• and
• adjusting the press molding apparatus so that the thickness of molded element is maintained;
• wherein at least one of the upper and lower molds comprises a matrix having a portion consisting essentially of β silicon carbide having a density of at least 3.20 g/cm3 whereby a molding surface is formed on the portion, the reproducing comprises grinding or polishing the impaired molding surface, and the adjusting comprises compensating the height of upper or lower mold which was reduced due to grinding or polishing.