The Beer–Lambert law says that the light a stone lets through falls off exponentially with path length: T = e^(−σℓ). Here σ is the absorption coefficient and ℓ is the path length.
In more detail
A longer path deepens every absorption. So a large or deep stone looks darker than a thin slab of the same material.
How we measure it
The simulator applies it per color channel along each internal path. The Dichroscope, Spectroscope and Polariscope apply it per wavelength along one straight path.
Related terms
- Absorption spectrum: An absorption spectrum shows which wavelengths of light a stone absorbs. In a spectroscope, the absorbed parts of the spectrum look dark.
- Pleochroism: Pleochroism is the property of a colored doubly refractive stone to show different colors in different directions. It happens because the stone absorbs its rays differently.
- 3D Gemstone Simulator: The 3D Gemstone Simulator is a free Digital Gemology tool that renders a cut stone as a camera sees it. You choose the cut, gemstone, carat weight, color, clarity, cut grade and lighting.