The method of making a transparent ceramic includes making a molded body from a powder mixture of starting materials, which include one or more sintering aids. The sintering aids can include SiO2, TiO2, ZrO2, HfO2, Al2O3 and/or fluorides. The transparent ceramic is made by pre-sintering the molded body at temperatures between 500° C. to 900° C., subsequently sintering in vacuum at temperatures between 1400° C. and 1900° C. and then pressurizing the sintered molded body at a pressure of from 10 to 198 MPa followed by annealing. The optoceramic material contains crystals with a stoichiometry of A2+XBYBYDZE7, wherein −1.15≦x≦+1.1, 0≦y≦3, 0≦z≦1.6 and 3x+4y+5z=8; and wherein A is a trivalent rare earth cation, B is a tetravalent cation, D is a pentavalent cation and E is a divalent anion.