Atreatment for improving the appearance and stability of porous gems is

Answer;

-colorless impregnation

Explanation;

-Colorless impregnation improves the appearance and stability or porous gems like jadeite. Sometimes a dye is added to improve color. Colorless impregnation involves filling of pores or other openings with melted wax, resin, polymer, or plastic to improve appearance, luster and stability. Commonly used in turquoise and jadeite. Dye could be added to the filler. This would be considered two treatments, impregnation and dyeing.

-The impregnation of a porous gemstone with a colorless agent (usually plastic) is meant to give it durability and improve appearance. Example:Stabilized turquoise