A Compendium of Useful Information for the Practical Man/Indian Lore/Stone Tools and Implements
Stone Tools and Implements used by the Luisenos Indians 
The ordinary pestle is merely a conveniently shaped stone, and the ordinary mortar a hole in a large flat granite rock near the dwelling. But many mortars are made of roundish boulders, mostly granite, though some are of tufa rock from a locality near the coast. So there are two kinds of mortars, the permanent ones of the large rocks, and others made from loose boulders, which, being portable, may be used where there are no large rocks near, or when, on account of bad weather, it is necessary to do the grinding under shelter.
In beginning to make a new mortar, arusut, the hole was not hollowed out at once to the required depth. A slight cavity was chipped in the rock, and a basin-shaped basket placed over it and glued in place with asphaltum or pitch, the sides of the basket keeping the acorns or other seeds from flying out when struck with the pestle. But with constant use the slight cavity made in the rock becomes deeper and deeper until the basket is no longer necessary, when it is removed. Many discarded mortars are found that have been worn clear through by continual pounding. Often on a large flat rock a number of mortar holes will be found, some of them of the usual depth, others only an inch or two deep, evidently just begun, while others may be a foot or more in depth, which having by continued use become too deep, have been abandoned and the new holes commenced.
One kind of mortar, tamyush, was used exclusively by the medicine men for pounding up the roots of jimson weed, Datura meteloides, for use at the boys' puberty ceremony. Some of these are quite symmetrical, being polished with considerable care, and some have even an attempt at ornamentation in the shape of grooves cut on the outside. The pestle of these mortars is also neatly shaped and polished. Another and very small mortar, tamya-mal, is said to have been used for mixing paint. This is also polished, and is almost exactly round.
It is a question whether the metates or grinding stones, ngohilish, now in use were employed prior to the arrival of the Mexicans. Some of the Luisenos think they were, while others say they were not, that their ancestors used only mortars. The rub-stone of the metate is called ngohilish po-ma, metate its-hand.
Flat perforated stones have been found. It is thought these were formerly used for cooking, the hole enabling them to be easily handled, when hot, by a stick thrust through them. They were probably also used for heating water.
A large stone tool has been found which may perhaps be called a stone adze. It weighs nearly eleven pounds, and was evidently intended to be used by being grasped with both hands.
Small sharp-edged flakes of a hard black stone were used as knives. Larger stones with a cutting edge were probably used for skinning or fleshing hides, but some are heavier than would be required for these purposes.