What are Freshwater cultured pearls?

Freshwater pearls are an organic gem which come from freshwater mussels living in rivers or lakes. They are produced in Japan on a limited scale, but are more widely farmed in China. The most desireable shape and colour is round and white preferably without blemishes. Lustre and size are also amongst the most important factors in determining value.

What are CZ Diamonds?

Cubic Zirconia is extremely rare in nature but widely synthesized for use as a diamond simulant, hence the name CZ Diamonds. 

Gem Type: Zirconium Oxide (ZrO2) 
Clarity : Internally Flawless
Treatment : Lab Created AAA Gem Grade
Hardness: 8.5 (mohs scale)
Specific Gravity : 5.8