9. Can I make out a Cubic Zirconia or American diamond from a real diamond?

Ans : The easiest way is to draw a line using a pen on a white sheet of paper. Place the diamond and the cubic zirconia on the line. If you see the line through the stone it is a cubic zirconia. Diamonds have the property to 'totally reflect' light and hence the line will not be visible. Other tests are also present.