Is Swarovski Zirconia a synthetic diamond?

Swarovski Zirconia is not a synthetic diamond, but it is commonly known as a diamond imitation.

How does Swarovski Zirconia compare to diamonds?

Swarovski Zirconia is the most diamond like Zirconia on the market.
An excellent diamond imitation for use in jewelry.
The two materials share a great number of similarities
and are very difficult to distinguish from one another. 

How does Swarovski Zirconia compare to Swarovski Crystal?

There are various differences between the two.
Swarovski Zirconia is very hard, heat resistant, and refracts light just like a diamond.
These characteristics make it the most popular diamond imitation. 
Swarovski Crystal is softer and less refractive and therefore different application techniques are used.