During the process of hydrothermal transport and recrystallization, an aqueous solution of sodium carbonate or sodium hydroxide is placed inside a large, electrically heated, pressure sealed container approximately 3 meters in height. Then, natural quartz fragments are placed at the bottom of the container as source material. Lastly, the upper portion of the container is a cage-like structure where small seed crystals of quartz are placed. When the container is heated (approximately 400 degrees centigrade), the crystal fragments which were placed at the bottom of the container dissolve into the aqueous solution of sodium carbonate or sodium hydroxide then crystallize onto the small crystal seeds - creating a new gemstone of hydrothermal quartz.
Even though hydro quartz is a real quartz, both being composed of silicon dioxide, it is important to appropriately identify natural quartz from hydro quartz. The best way for consumers to distinguish between the two is by looking at the clarity, color, and size. For example, hydro citrine or amethyst can come in unnaturally large sizes and still have perfect clarity. On the other hand, natural citrines and natural amethyst may include slight imperfections, with some color variance. Also, hydrothermal quartz can also come in colors not found in nature, including some interesting multi-colored combinations.