Sunsets over the sea may also be orange due to salt particles in the air which are effective Tyndall scatterers. The sky around the sun is seen reddened as well as the light coming directly from the sun. This is because all light is scattered relatively well through small angles but blue light is then more likely to be scattered twice or more over the greater distances leaving the yellow, red and orange colours. A blue haze over the mountains of Les Vosges in France. Sometimes there may be other particles in the air which are much smaller.
Some mountainous regions are famous for their blue haze.
A forest fire or volcanic eruption may occasionally fill the atmosphere with fine particles of 500-800 nm across which are the right size to scatter red light. This gives the opposite to the usual Tyndall effect and may cause the moon to have a blue tinge since the red light is scattered out. This is very rare, literally once in a blue moon. The Tyndall effect is responsible for some other blue coloration' s in nature such as blue eyes, the opalescence of some gem stones and the colour in the blue jay's wing. The colours can vary according to the size of the scattering particles.