Weight from volume is how we calculate a model's weight: m = V × ρ ÷ 200 carats. V is the volume in mm³ and ρ the specific gravity in g/cm³.
In more detail
The 200 comes from 1 carat = 0.2 g and 1 cm³ = 1,000 mm³. At a given shape, weight scales with the cube of size, so twice the size weighs eight times as much. At its reference size, the T73 weighs 1.99 ct in diamond and 3.28 ct in cubic zirconia.
How we measure it
Each build measures every model's volume from its mesh, by the divergence theorem over its triangles. The simulator scales the model by the cube root of the weight ratio to reach the carat weight you choose.
Related terms
- Specific gravity: Specific gravity compares a stone's weight with the weight of the same volume of water. It decides how much a stone of a given size weighs.
- Reference size: The reference size is the size at which a 3D model is delivered, in millimeters. Our cut pages give it, with the model's weight at that size in each gemstone.
- Carat weight: Carat weight is the weight of a gemstone. One carat is 200 milligrams, a fifth of a gram, and it has 100 points.
- Mesh: A mesh describes a 3D surface as many small flat triangles joined at their edges. STL, OBJ, FBX and GLB files store a mesh.