Diamond cut prices generally vary depending on how much of the diamond crystal is wasted during the cutting process. A princess cut diamond is normally priced lower than a round brilliant cut diamond, as there’s very little diamond lost, and the crystal structure is an octagon, so it has a square cross-section. A round brilliant cut diamond does have more wastage as you’re cutting a circle from an octahedral profile, but not as much wastage as other cuts, such as a pear or a marquise, so it tends to sit in the middle of the range for pricing, although demand can also make prices rise.