Fishing was an important activity in Māori life, as shown by the numerous fish hooks of bone and shell found in some archaeological sites. Stone trolling lures (also called minnow lures), with bone or shell points attached, were used to catch fish such as kahawai and barracouta. They were commonly made from argillite, schist or greywacke, but also from other materials, including limestone and serpentine. Stone sinkers were made by forming a shallow groove around a pebble or cobble and winding a line around it. Large stones were occasionally used as anchors, and pumice as floats for fishing nets.
Māori used stone extensively for gardening. They added sand and gravel to garden soils, to make them friable, retain moisture, and improve their heat retention – critical for subtropical plants growing in New Zealand’s temperate climate. Called plaggen soils, these are most extensive along the Waikato and Waipā rivers. Here, sand and gravel dug out of old river terraces were placed in hollows in the topsoil up to 30 centimetres deep, and the excavated topsoil placed on top, forming a mound.
Cobbles and rough stones were used to make low, elongated rows 1–2 metres wide and up to tens of metres long. These were usually in groups, called stone row systems, and were laid out more or less parallel, often in association with circular stone mounds 1–2 metres in diameter.
Some stone rows appear to mark garden plot boundaries. Other stones were dug from nearby underground deposits (leaving well-defined borrow pits), or brought from streams or river beds and put into purpose-built shallow trenches. The excavated soil was then replaced over the stones. Like the plaggen soils, the stones improved heat retention and warmed the soil above them, and the rows themselves were probably gardened.
One valuable plant was flax, which was prepared for use as a fibre by beating it with stone pounders (patu muka). These pounders were often made from greywacke or volcanic rock.
Rounded stones were widely used in cooking, particularly in earth ovens (hāngī or umu). Hāngī stones were often carefully selected because certain rocks explode violently when heated in a fire. Good stones would sometimes be presented as a gift to other tribes. Volcanic rocks were the most suitable, while greywacke was also used. At Ruarangi in Northland, they were considered so well-suited for the task that they were described as ‘stones crying for food’ (ngā kōwhatu tangi kai o Ruarangi).
Stones were also used to boil water. They were heated in a fire, then put into the vessel containing water.
Water-smoothed cobbles (autoru) were used for crushing kōkōwai, a naturally occurring red or yellow iron oxide. The powder was used in body painting and on carvings, and stored in pumice pots. Red kōkōwai or ochre is still used on carvings.
For entertainment, children and adults used spinning or whipping tops, generally made from pumice but also greywacke, volcanic rock, and wood. They were spun with a flax whip. Some nose flutes (nguru), particularly those found at Ōruarangi on the Hauraki Plains, were also made from stone, including sandstone, pumice, and hard volcanic ash.