Locate each part of the diamond
The crown is the upper part of a diamond above its girdle, while the pavilion lies below it. Their angles describe different slopes, usually expressed in degrees. When comparing round engagement rings, locate both parts on the report diagram before comparing the figures. Neither angle is a measurement of the ring's height above your finger.
Consider the relationship
The way a diamond returns light depends on relationships between proportions, not one angle in isolation. GIA discusses crown and pavilion angles as interacting parts of round brilliant cut assessment. A useful enquiry asks how the whole stone performs, rather than treating a preferred figure found online as an independent guarantee of brightness, fire or an overall cut grade.
Keep percentages separate
Crown height and pavilion depth may also appear as percentages on a diagram. Those figures are not simply alternative labels for the angles. Copy the field name, value and unit together when making a shortlist. This avoids comparing a number in degrees with a percentage merely because both appear near the same region of the illustration.
Return to the finished ring
Use clear ordinary-lighting views to compare the actual stones and settings. If an angle needs explanation, ask about the report for that particular option rather than trying to measure a sloping facet in a photograph. In CIELA's ring collection, read the supplied specifications individually. An understanding of the diagram should make the choice more informed without replacing the appearance you enjoy wearing.
Further reading: GIA.
