Final answer:
Limestone is primarily composed of the mineral calcite, which reacts with dilute hydrochloric acid, causing limestone to fizz. Additional minerals may include impurities like chert, affecting its appearance and weathering properties. Limestone has been a popular construction material historically.
Step-by-step explanation:
Limestone is composed primarily of calcite, which is a form of calcium carbonate (CaCO3). This mineral is essential for the rock's formation, often originating from marine organisms such as coral, clams, and other sea-life that have calcite skeletons. When limestone comes into contact with dilute hydrochloric acid, it is known to fizz due to the reaction between the acid and the calcite in the limestone.In addition to calcite, limestone can contain various other impurities and secondary minerals, such as silica or chert, which can make the rock appear different and behave differently when weathered. For instance, chert is a very hard material that typically weathers to a brown color and is found in nodules within limestone. Furthermore, limestone has a variety of uses, including in construction, where it has been used extensively throughout history due to its availability and durability.