Depth proportion: In attempting to quantify a gem’s proportions, reference is usually built to depth share. This is calculated by using the depth and dividing it from the girdle diameter (or common diameter, in the case of non-round stones). The appropriate array is mostly 60–80%. Dispersion (‘fire’). This entails splitting https://www.gemsbiz.com/blog/explore/a-guide-on-diamond-quality-grading-parameters