Final answer:
Shale is not a type of limestone. Limestone is primarily composed of calcite and includes varieties such as coquina, micrite, chalk, and travertine, whereas shale is a fine-grained sedimentary rock rich in clay minerals and silt, distinct from limestone.
Step-by-step explanation:
The type of limestone that is not listed among the varieties of limestone is d. shale. Limestone is a sedimentary rock composed mainly of skeletal fragments of marine organisms such as coral and mollusks. The main mineral found in limestone is calcite (CaCO3), which fizzes when it reacts with dilute hydrochloric acid. Types of limestone include:
- coquina: Composed mostly of shell and coral fragments.
- micrite: A fine-grained limestone.
- chalk: Made up of the shells of microscopic marine animals (foraminifera) and marine algae (coccoliths).
- travertine: A form of limestone deposited by mineral springs.
On the other hand, shale is a type of sedimentary rock characterized by its fine-grained texture and rich clay minerals and silt particles. It is different from the texture and composition of limestone and does not belong to the limestone category.