Abstract: A conversion-to-oil apparatus capable of efficiently treating plastic, includes a melting unit for heating and melting plastic fed thereto and a decomposing unit for further heating and vaporization-decomposing the molten plastic melted by the melting unit, wherein the decomposing unit is inclined upwardly, having a lead screw mounted therein, and is provided at its upper end portion with a catalyst cylinder extending upwardly and a residue takeout unit extending downwardly, and the decomposing unit has a prevention element for preventing molten plastic gas from flowing down to the residue takeout unit.

Abstract: A conversion-to-oil apparatus capable of efficiently treating plastic, includes a melting unit for heating and melting plastic fed thereto and a decomposing unit for further heating and vaporization-decomposing the molten plastic melted by the melting unit, wherein the decomposing unit is inclined upwardly, having a lead screw mounted therein, and is provided at its upper end portion with a catalyst cylinder extending upwardly and a residue takeout unit extending downwardly, and the decomposing unit has a prevention element for preventing molten plastic gas from flowing down to the residue takeout unit.

Abstract: As an ornamental material, use is made of a single crystal represented by a chemical formula RVO4, where R is at least one rare earth element selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.