Clay

You need clay for several pottery products. The quality of the products made by the clay is based upon the quality of the clay, the kiln used, and the branches provided to fuel the kiln; the quality is also soft- capped by the dexterity of the pottery craftier. The only way to get higher quality clay is to find certain shallow areas that produce higher quality clays. For more information on finding high quality clay, go to this link.

As of the May 30th Clay update, clay has been diversified into multiple 'species' of clay, though like String, they all serve the same purpose and all existing recipes that call for clay will accept any form of clay.

Clay forms are as follows:
 * Acre Clay - Dig up on Mudflats
 * Ball Clay - Dig up in the shallow water of rivers or lakes
 * Bone Clay - Must be crafted
 * Cave Clay - Appears in shallow water in caves
 * Gray Clay - Appears in any shallow surface water

Also, the clay update made the Nature/Industry personal belief slider influence the success rate of gathering clay. With full nature, success rate is 0.5x the normal, and with full industry, the success rate is 2x the normal- you can gather two clay from each Gray clay and Cave clay node.

How to Acquire
Ball clay can be acquired by digging in shallow water, and Acre clay can be acquired by digging on Mudflats. Each of the listed areas holds 0-1 unit of clay, except for areas with a clay quality point that hold larger amounts. Therefore when digging be on the watch for clay with quality 10 and up. At these clay deposits, the character can continue extracting clay until either the inventory is full or the player can instruct the character to do otherwise. On the first dig in a clay yielding area, you will get 1 clay.

Digging from a clay deposit can slowly reduce the quality of the point also. Once the quality drops to 10, further digging will exhaust that part of the deposit.

It takes approximately 3.5 seconds to dig up one unit of clay.

If you go to an island in a river and dig around it, it is the jackpot for Ball clay.

Gray clay and Cave clay are not dug up like conventional Ball and Acre clay, but instead appear as nodes in the same manner Mussels and other do. To gather them, you have to "Pick" them, as you would with plants.

Bone clay is crafted, from five units of Bone ash (produced from bones fired in a kiln), one Cave clay and a single Feldspar. The quality of the produced Bone clay is influenced by your Intelligence and Perception, and appears to be affected by the quality of the Feldspar more than the quality of the other ingredients.

According to Loftar, currently the quality of Cave Clay plays little or no part in Bone clay quality, as it is always 10, because there are no quality points for clay within caves yet, though this is likely to change in future.