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What is the difference between diamonds and cubic zarconia?


Cubic Zarconia's (or CZ's) are most commonly known for their visual likeness to a diamond. They are artificial or man-made stones that offers an alternative to the light and bright appearance of diamonds. They are however not diamonds and far less expensive.


Cubic zirconia (CZ): Crystalline zirconium dioxide (ZrO2). It's relatively hard, very clear, visually resembles a diamond and very cost effective. It comes in various colors and shapes. The most common shapes are round cut, princess cut, pear cuts and baguette cut.


Knowing the key differences between a cubic zirconia and a diamond can save you a lot of money. Unfortunately there are cases where a diamond ring or an engagement ring is advertised with a diamond when in fact it is made with cubic zirconia's. While cubics have a place in the market, they can confuse and often cost a client who is spending good money on what they believe is a diamond.

There are a number of tests to see the difference between cubic zarconia's and diamonds.

1: Glass test: Run a stone along a piece of glass. If the stone seems slightly damaged and the glass relatively unscathed, the stone is likely to be a cubic (CZ). A diamond would damage the glass and remain unscathed. The downside to this test is that something will be damaged - either the stone or the glass.

2: Transparency test: The second test has to do with the transparency of the stone. Diamonds are cut to produce many facets that reflect light, making it almost impossible to see through. Hold the stone over text in a magazine - if you can read the text through the stone, you're most likely holding a cubic zarconia. If you can't read the text at all, it's likely that you're holding a diamond.

3: The fog test: This is our favorite and is also the easiest test to perform. Simply breathe on the stone. Diamonds are incapable of holding heat and won't fog-up. Cubics on the other hand retain heat easier and will fog-up.

4: UV test: If held under a UV light, a diamond will show a certain amount of florescence (Purple glow). A cubic on the other hand will show no florescence at all.

Whilst there are other test as well - these appear to be the quickest and easiest.


Cubic Zarconia's are used more regularly in dress rings and costume jewellery rather than engagement rings or wedding rings.
They do however act as an effective placeholder for real diamonds. You might find the engagement ring you desire but don't have the funds available. The same ring can be designed and manufactured with a cubic zirconia and later replaced for a real diamond.


In recent times it has become common-place for jewelers to refer to stones as Tanzanite Cubics, Ruby Cubics or something closely representing a precious or semi-precious stone. This is done to create confusion and make you believe that you're buying more than just a cubic. The fact is that these stones don't exist. Be wary of any descriptive name containing cubic or it's abbreviated version "CZ".


Before you consider buying an engagement ring or dress ring, ask a professional for advice.

Cubic Zarconia, Cubic Zarconium, Cubic Ring, Engagement ring

Diamonds VS Cubic Zarconia

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