Opal phytoliths of New Zealand

Opal phytoliths are particles of opal (amorphorous hydrated silica) that develop in the tissues of plants. These particles take on a fascinating variety of shapes depending on the type of plant in which they form. When plants decay, opal phytoliths accumulate in the soil and provide a record of the plants that once grey there. They have proven and potential value in a wide range of research in palaeoecology, but have received little attention in New Zealand. In some countries, they are also being used as raw materials for modern industrial products. This guide provides many microscopic photographs to aid identification.