MDC (Multi-Dimensional Directional Crystallization) cultivated gemstones are a gemstone growth method developed for the high-end jewelry market, which is identical to natural gemstones in terms of chemical composition, physical properties and optical properties. Compared to natural gemstones, cultivated gemstones are internally cleaner, free of impurities and fissures, and do not need to undergo artificial optimization treatments such as diffusion, filling, irradiation, high temperature heating, etc., which are necessary for most natural gemstones. They are far more cost-effective than natural gemstones. Traditional synthetic gemstones such as: flame fusion, lifting, hydrothermal, co-solvent, bubbling, cold crucible, etc. have obvious identification features visible to the naked eye, such as: elongated dumbbell-shaped bubbles, curved growth lines, crucible metal residue, co-solvent residue, etc. MDC cultivated gemstones do not have synthetic gemstone identification features, and the color is different from that of synthetic gemstones floating on the surface, neither the naked eye nor simple instruments can accurately distinguish them from natural gemstones. Neither the naked eye nor simple instruments can accurately distinguish them from natural stones. At the beginning of the product launch, the domestic gemstone appraisal organizations (including the NGTC) could not accurately appraise it, and the appraisal results were all natural gemstones. MDC Grown Gems is the first and only gemstone that has been professionally recognized by GUILD Gemological Laboratory in the U.S.A., and has obtained the GUILD Grown Gemstones Certificate (Lab-Grown Corundum).