主权项 |
1. An oblong precious stone elongated in one direction and defining a length of the precious stone in said one direction and a width in a direction perpendicular to said one direction, the precious stone having a left side and a right side both of which extend along the length of the stone, the precious stone comprising:
a table having a table plane, elongated in the one direction, a girdle, and said precious stone having a shape and configuration that results in a specific total depth percentage, a specific crown height percentage, a specific girdle height percentage and a specific table percentage; a first crown surface, elongated in the one direction and extending at the left side of the stone and located between the table and the girdle and extending at a crown angle to the table plane; a second crown surface, elongated in the one direction and extending at the right side of the stone and located between the table and the girdle and opposed to the first crown surface and extending at said crown angle relative to the table plane; a first pavilion surface, elongated in the one direction and extending at the left side of the stone and at a pavilion angle relative to the table plane; a second pavilion surface, elongated in the one direction and extending at the right side of the stone and extending oppositely to the first pavilion surface and extending at said pavilion angle relative to the table plane; wherein said crown angle is in the range of 30-36 degrees and wherein said pavilion angle is in the range of 30-34 degrees; and wherein said crown angle and said pavilion angle are so formed that the crown angle is either equal to or larger than said pavilion angle by an angle that does not exceed 6 degrees, to attain increased light amplification. |