When we speak of cut we are more interested in the proportions of the diamond as opposed to its shape (Round Brilliant, Marquise, Pear, Princess, etc.) Every diamond regardless of its shape gets it brilliancy and scintillation by cutting and polishing the diamond facets to allow the maximum amount of light that enters through its top to be reflected and dispersed back through its top as shown above in the “ideal cut”. As you can see, if the angles are correct the light that enters is dispersed properly back through the diamond’s top facets. When a stone is cut too deep or too deep the light that enters through the top is allowed to escape through the diamond’s bottom and does not allow the maximum beauty of the diamond to be realized.