White clay is used interchangeably with red, but the two are never mixed. It is obtained in the bad-lands to the northeast of San Ildefonso, from the side of an arroyo at some distance from the village. The Indians dig it, bring it home, and prepare it in exactly the same manner as the red clay. The color, when dry, is greyish white; when wet, brownish grey.
Temper
The Indians of San Ildefonso obtain their tempering material from outcrops along the Santa Fe-Española road, in the vicinity of the landmark known as Camel Rock. Near the crest of the first high hill crossed by the road north of Camel Rock, just west of the road, in the eastern bank of the cut of the old abandoned road, is a small cave made by the digging of this temper ([pl. 10], a). There is another outcrop in the ridge of which Camel Rock is a part. This mineral is a very light grey in color. When freshly exposed to the air it is soft and crumbly—fragments as large as the fist can be crushed in the hand—but after being exposed for some time it hardens. When chopped out with an axe or hatchet it takes the form of small fragments and fine powder. There are veins and nodules of a hard yellow rock in the stratum, which are chopped out and thrown away. The source of the temper is at such a distance from the pueblo that trips to it are made only at long intervals when a large quantity is secured in cement-bags, and carried home in a wagon. Two cement-bags may be filled with from fifteen to twenty minutes’ work at the quarry.
Some of the Indians, while still at the quarry, pound the temper with an axe or hatchet, or a stone, to break the larger pieces and remove the coarser impurities. Others wait to clean it until reaching the house. In the latter case the temper is spread on a cloth or skin; the skin being preferred as offering a smoother, more resistant surface. It is then broken up by trampling it with moccasined feet. Formerly the Indians ground the temper on their metates. The final step in the preparation is to pass the material through a sieve to remove the smaller impurities such as sand and crushed rock. Before the sieve was known, the Indians spread the temper in a very thin layer on a board or skin, and went over it carefully and painstakingly with their fingers, feeling for any slight irregularities or rough places. The temper when cleaned is a fine powder, which looks and feels like dry cement. It is stored in old cement-bags ready to be mixed with the clay.
The purpose of the addition of tempering material is to counteract the tendency of the pure clay to crack during the shrinkage that takes place in sun-drying and in firing. If, however, there is too much temper, the clay becomes “short” and loses its adhesiveness. The Indians understand this fully, for if vessels crack badly during sun-drying, they are ground up, and more temper is added to the paste before it is used again; if, on the other hand, a pot will not retain its shape while being moulded, it is pulled down, more dry clay added to the paste, and the mass rekneaded.[10]
Cooking-Vessel, or Apache, Clay
This is very different from the two other kinds of clays used. It is light brown in color, with a large quantity of fine mica flakes in it[11]; it also has a distinctive odor. When wet it smells cleaner and fresher than the red or white clay, like a newly plowed field after a shower. Some of the San Ildefonso Indians obtain this clay from Las Truchas, a mountain district to the northeast of the village[12]; others get it from Santa Fe Canyon. It is dug either with the hand or with a small stick, and is brought to the pueblo in the form of small lumps. While still in this condition, it is stored in vessels or bags.
The preparation for use is very different from that of the other clays. The lumps are put in a receptacle, such as an enameled washbasin, and sufficient water is added to saturate them. If too much water has been mixed in, the mass is put in the sun to dry out for a while. After the clay has been thoroughly softened by the water, the next step is to remove the pebbles. A small handful is carefully and slowly squeezed and kneaded in the left hand, while the thumb and forefinger of the right are used to pick out the numerous small pebbles as they are encountered. After most of these have been removed, the clay is put on a canvas or skin, and a small part of it at a time is flattened out with the heel of the right hand, pressing away from the body, and against the cloth or skin so as to produce a very thin layer, in which the smaller pebbles are readily felt and from which they can easily be eliminated. Finally when this has been done with all the clay, the whole mass is kneaded together, just as the red and white clays are kneaded. When a uniform consistency has been attained—that of putty—the mass is ready for use. The removal of pebbles and the kneading consume from one-half to three-quarters of an hour. The pebbles which have been removed are placed in a small lard-pail containing water, and when the clay adhering to them has dissolved, they are thrown away and the clayey water is used in the process of moulding the paste.
The most important difference between this clay and the others is that no temper of any kind is mixed with it; the clay, after being cleaned, is used in the vessels just as it came out of the claypit. The fine mica flakes probably act as temper.