Which shapes are most prone to chipping? I know princess cut and marquise cut, but are there any others? Is an emerald cut prone to chipping? Thanks!!!
Cutting style or finish details may make any diamonds prone to chipping. Diamond is a brittle material. Consider any sharp edge or sharp point problematic. The tips of marquise, heart or pear shapes. The right angle points of princess, the tips of sharply pointed triangular shapes. Shallow crown angles combined with very thin girdles have an ill effect on all diamonds including round stones.
Real breakage is reasonably rare. Slight chipping is not uncommon. Insurance generally covers these situations when they occur. If you go without insurance you are either knowingly self-insured or potentially in line for a loss. These losses are not common, but when it happens to you, the odds don''t really matter.
As David said, any shapes with sharp edges. Also, diamonds with large inclusions (such as a large feather in the table) etc. I believe are more prone to chipping as well.
Pear shapes are probably the most risky of all. Obviously this is only in the case where the point is set. They are far more tricky to set then squares for instance, as the one point is supposed to secure all of the front. They are usually set with a V'' tip which will need to be substanstial enough for the purpose and the tip must be brought downwards endangering the whole point.
Emerald cuts and other square stones chip along the edges at thin girdles while being worn in exposed settings because those long sidess are cleavage directions in the diamond crystal.