gems, jade, synthetic jadeite, fei cui, synthetic fei cui, reconstructed jade, HPHT

This invention proposes a method for preparing reconstituted jadeite. It involves refining offcut fragments of natural jadeite and using magnetic separation to remove magnetic black or dark-colored substances from the jadeite powder. After batching, the raw materials are mixed evenly in a mixer and then subjected to low-temperature high-energy ball milling. Lead-free, colorless glass is then added, followed by a second round of ball milling. The final powder is pre-pressed into a compact, which is placed in a high-pressure hydrothermal autoclave for sintering at a temperature of 350°C to 500°C and pressure below 45 MPa. The coloring agent used is natural jadeite with a high chromium content (mass fraction 1–5%), and the lead-free, colorless glass acts as a binder (mass fraction 1–10%). This invention enables efficient utilization of scarce resources by reconstituting natural polycrystalline jadeite aggregates through high-pressure hydrothermal processes, producing large-volume, well-colored products that closely resemble natural jadeite while preserving its crystal structure.