Proportions of the finished stone are important to produce the best result. If the pavilion is too deep, the center of the stone will appear dark and if is too shallow, the stone will appear washed out. A diamond appraiser will determine the weight of the properly proportioned stone that can be derived from a finished stone and use that as the weight of appraisal. The cost of refashioning the diamond to a properly proportioned stone is then deducted from the evaluation. This prevents the lapidary from inflating the price of the stone by inflating the weight.
Diamonds are useful for several geological purposes.
Thus, inclusions in diamonds may provide some examples of the mantles makeup. Some geologists have suggested that the distribution of diamonds between continents shows examples of spreading ocean basins and provides strong evidence for plate tectonics. Oval brilliant cut. Round brilliant cut. Uncut octahedral diamond crystals.