SAM Daily Times

Snow is white but Ice has no colour, although both are solid states of the same substance of water. Why is that??

The main difference for the difference arises from the degree of smoothness of snow and ice. Matter obtains its look by its interaction with surrounding light and the way this interaction influences the light that gets to our eyes.

There are four types of interaction, one of which is "scattering". It is the scattering of lights that accounts for the difference in colour between snow and ice.

Each individual ice crystal has colour. Its not quite colourless but very pale blue-green. The colour is more apparent when you see a very large piece of ice , such as the interior of a glacier. A smooth piece of ice absorbs a little light, but has few other interactions with light, so it looks transparent and almost colourless.

Snow is composed of many ice crystals which makes snow's overall structure quite rough. This roughness increases the scattering of light that hits snow. Although each crystal refracts, or bends, light and disperses it into its colours, when many small colours refract , the colours mix again, leading to a white appearance.

Source: RD ASIA