Melt processes are some of the oldest and most commercially important processes for creating synthetic gems. Cubic zirconia is made using a radio-frequency "skull crucible" system, a specialized melt process.  Skull melting is a type of super-hot melt process used to produce the most widely accepted diamond imitation: cubic zirconia (CZ). Zirconium oxide, the main component in cubic zirconia has a extremely high melting point (approximately 4980'F), Conventional melt crucibles (which have lower melting points) cannot be used. Thus a special process was developed to handle these high temperatures.  Basically, zirconium oxide powder is placed in a container formed of water cooled copper pipes. Metallic zirconium is then placed in the center of the powder and melted using high frequency radio waves. This in turn causes the zirconium oxide powder to melt from the center outward (like a microwave heats food). In effect the powder touching the copper pipes forms its own crucible. As the remaining material inside the zirconium oxide shell cools, the cubic zirconia crystallizes. (Cooling this extremely hot molten ore becomes the most crucial step in the entire process. A carefully programmed cooling procedure is required to form the flawless crystals that are subsequently transformed into exquisite cubic zirconia gemstones). Cubic zirconia is usually internally flawless, but sometimes  gas bubbles, partially or completely filled with zirconium oxide can be seen. There are a number of manufacturers of CZ including   Ceres Corporation (Massachusetts, US), Singh Industries (New Jersey, US), Taiwan Crystal (Taiwan), and The Commonwealth of Independent States (formerly the USSR).   Each manufacturer uses the above described process, but each also has proprietary "recipe additives" that slightly alter  the different aspects of  the resultant cubic zirconia. 

How can you  tell the difference between a Cubic Zirconia and a Diamond:

• Cubic zirconia can be identified by a specific gravity test of a unmounted stone.
• Cubic zirconia can be identified by marking ink on the table (flat top) of the stone; on cubic zirconia the ink beads up.
• When gem printed, cubic zirconia photographs the reflective and refractive pattern.
• When measured for heat conductivity with diamond probe, cubic zirconia and other imitations register red on the indicator; diamond registers green.

Absolutely! The quality of the cubic zirconia is based on the purity of ingredients, the proportions of the formula, and the temperature and pressure at which the elements are combined. Each stage is critical in the production to insure the best outcome.

Will my Cubic Zirconia Cloud up or change color over time?

The Cubic zirconia are covered by a Lifetime Guarantee to retain their original brilliance and luster under normal wear. In the unlikely event this should ever happen, we will provide a replacement gem at no charge.  

Natural skin oils, soap, and dirt cause a film that dulls the beauty and luster of the cubic zirconia, just as it dulls real diamonds. Cubic zirconia is very durable and can withstand most chemicals.  We suggest weekly cleaning using liquid dishwashing detergent or a commercial jewelry cleaner (preferably without ammonia). 

Specifications:

Because cubic zirconia  is so dense and solid, it outweighs a diamond of the same millimeter size, weighing 1.7 times more than a diamond of the same millimeter diameter.

• Hardness (Moh's scale) 8.5
• Specific gravity: 5.8
• Refractive index: 2.15
• Dispersion:   0.060

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Last modified: November 20, 2009