Glass objects from ancient civilizations appear milky or cloudy instead of transparent due to along process of weathering or devitrification. This happens because the glass has been exposed to moisture, air, and soil chemicals for centuries. This prolonged exposure leads to the following effects:
- Chemical reaction: The surface of the glass reacts slowly with water and atmospheric gases.
- Structural damage: These reactions result in the formation of micro-cracks and crystalline patches on the glass surface.
- Light scattering: These surface changes cause light to scatter, making the glass look milky, frosted, or iridescent instead of clear.
