Loading data...
Like color and luster, the transparency of a mineral is fundamentally dependent on its atomic composition . In metallic bonds, the free electrons block light immediately at the surface (reflection/absorption). In non-metallic minerals, the transition metals (copper, iron, etc.) determine how much light is absorbed and what color remains.
Besides the chemical composition, defects in the crystal lattice, such as vacancies or grain boundaries, also play a role. They can either absorb additional light as color centers or deflect the light at a microscopic level.
Finally, macroscopic inclusions such as cracks, gas bubbles, liquids or foreign minerals in the mineral also lead to a reduction in transparency, as they can diffusely deflect the light in all directions or block it completely.
Transparency is difficult to quantify in reality and is highly dependent on the subjective perception of the observer. For the sake of simplicity, we have characterized three levels in our system: transparent, translucent, and opaque.