Dark Brown rocks have the richest iron, with no water content.

Red rocks have less iron than the dark brown rocks.

Orange rock results when the iron is bonded with water.

Yellow means the rock probably has less iron than the orange.

White sandstone rock has had most of its iron content removed.

White stains on the rock show nesting or roosting places of small birds of prey.

Blue-green leaves indicate the presence of a waxy coating which guards against water loss.

White clay particles gives the clay pan its bleached appearance.

Yellow spinifex indicates that the country is experiencing a dry period.

Source: NT Parks and Wildlife signage