Historically, rubies have symbolized passion, power, and protection, often being referred to as the “king of gemstones” in ancient cultures. Interestingly, rubies owe their rich red color to traces of chromium. At RG Crystals we are able to produce high-quality corundums using three advanced growth methods. Depending on the production technique, our gems are classified as lab grown or synthetic, highlighting their origin and unique characteristics.
 

Lab Grown corundums are created with Czochralski and HDSM Methods. The Czochralski Method involves placing a seed crystal above the melt's surface. When it contacts the melt, the seed is rotated and slowly lifted at a controlled speed. Heat reduction through the crystal, while maintaining the melt temperature, causes gradual crystallization. The crystal grows downward as it’s pulled, with synchronized pulling speed and crystallization rates ensuring a uniform, continuous crystal lattice. This method ensures precise chemical composition and optical clarity, suitable for high-end jewelry. In HDSM, a flat-bottomed crucible with short sidewalls is used. A seed crystal at the pointed end initiates growth, as this area cools first, forming a single crystallization center. The crystallization front moves through the melt as the container shifts relative to the heater, pushing impurities to the opposite end. The result is a purified crystal, with directional crystallization occurring in horizontal or vertical configurations based on the container’s orientation. This technique is particularly suited for large oxide crystals and is effective for producing materials with high optical and structural quality.

The flame fusion process, used to produce synthetic corundums, is the oldest and most cost-effective method. Powders of the required chemicals and colorants are melted in a hydrogen flame and dripped onto a seed crystal. Crystallization occurs where the molten drops contact the seed, forming round single-crystal boules. This method produces vibrant corundums at a fraction of the cost, suitable for mass-market jewelry.