clay crystal in a sentence

1. However, those enzymes too may be trapped on the clay crystals.
2. Although they may have a large water content, it is bound to the surface of the flat clay crystals comprising the shale.
3. The book popularized a hypothesis he began to develop in the mid-1960s that self-replication of clay crystals in solution might provide a simple intermediate step between biologically inert matter and organic life.
4. It's difficult to find clay crystal in a sentence.