Why Cubic Zirconias (CZ) and Lab Diamonds are Not the Same Thing

What is the difference between lab diamonds and cubic zirconia?

Quite simply, a laboratory-grown diamond is a diamond: carbon atoms arranged in a diamond cubic crystal structure. The only difference between mined diamonds and lab grown diamonds is the origin of the diamond. Grown diamonds and mined diamonds have the exact same physical properties.

A cubic zirconia is not a diamond.  It is merely a diamond simulant, meaning that it looks similar but not exactly like a diamond. In fact, a cubic zirconia contains zero carbon, whereas diamonds (mined and grown) are made entirely from carbon.

Put another way, cubic zirconia is a cheap imposter to a diamond that is a different material entirely; whereas a synthetic diamond from Ada Diamonds is chemically and optically indistinguishable from a mined diamond.

Is There Anything Wrong with Buying A Diamond Simulant or Cubic Zirconia?

No, as long as you know that is what you are purchasing, and only if you are spending very little. Diamond simulants like cubic zirconia (and coated CZ sold by companies like Diamond Nexus Labs) are extremely inexpensive to produce. These products are typically $2.50 per carat at wholesale from distributors like Stuller and yet they can retail online for over $100 per carat. That is a total rip off for what you are getting! Diamond simulants will also fade, scratch, and change color over time and are not a long-term option for fine jewelry.