| Much of Italy contains Pliocene clay, which is good for pottery and brickmaking. |
| The brickmaking shales are those which are sufficiently rich in clay to form a plastic paste when ground and mixed with water. |
| A beginning had been made, however, and some knowledge of brickmaking gained. |
| The 'Oxford clays' are valuable for brickmaking when their use is understood, but to the uninitiated they are very troublesome. |
| The chief clay in this System is the gault, a stiff, black, calcareous clay of marine origin chiefly used for brickmaking. |
| These clays are closely allied to those used for brickmaking, but are somewhat finer in texture and more plastic. |
