American Brilliant Cut
A label that has come to refer to fashioned diamonds with the proportions and facet angels that were worked out by trial and error by master American cutters, to yield the maximum in brilliancy consistent with a high degree of fore and confirmed mathematically by Marcel Tolkowsky. It should not be inferred from the name that such stones are cut only in America, or that most stones that are cut in America conform to these standards. Unfortunately, this term has also been used to describe spread ie. thin crowned diamonds.