Diamond Weight Estimation

This is for estimating the weight of loose diamonds. I am searching for the formula for rose cuts, which are basically cabochons covered with triangular facets coming up to a point.

This section of my site was originally "Gemstone Weight Estimation", but I realized the formulas were meant for diamond. I know formulas for other gemstones exist, but I don't know what they are, or I would post them here.

3.52 is the specific gravity of diamond.

1.) Round faceted stones ... diameter × diameter × depth × 3.52 × 0.0018

2.) Oval faceted stones ... diameter × diameter × depth × 3.52 × 0.0020
(To get the diameter of an oval, average out the length and width)

3.) Step-cut faceted stones ... length × width × depth × 3.52 × 0.0025
(This is for step cuts with cut-corners, aka emerald cut stones)

4.) Rectangular faceted stones ... length × width × depth × 3.52 × 0.0026
(I.E. rectangular princess cuts, etc.)

5.) Square faceted stones ... length × width × depth × 3.52 × 0.0023
(I.E. Princess cuts, quadrillion cuts, etc.)

6.) Marquise faceted stones ... length × width × depth × 3.52 × 0.0016

7.) Pear faceted stones ... length × width × depth × 3.52 × 0.00175

8.) Square cushion faceted stones ... diameter × diameter × depth × 3.52 × 0.0018
(Measure between one corner to its diagonal corner, and the other to the other, average them to get diameter)

9.) Rectangular cushion faceted stones ... diameter × diameter × depth × 3.52 × 0.0022
(Average the length and width to get the diameter)

10.) Square step cut ... diameter × diameter × depth × 3.52 × 0.0023
(Average the length and width to get the diameter. This is for square, four-sided stones.)

11.) Rectangular step cut ... length × width × depth × 3.52 × 0.0025
(I.E. baguettes, etc. This is for rectangular, four-sided stones.)