A square shape is the second most popular diamond cut style after the round brilliant cut in modern times. 
Each elongated facet can create a "mosaic pattern" effect when reflecting light. 
The cut is typically based on a 1:1 square ratio, but slight variations exist due to the optimization from the rough diamond. 
This cut style offers a delicate sparkle when it catches light and a clean appearance on the hand due to its straight-lined square shape.