Answer:
One good example of a mineral formed by an organism is calcium carbonate (CaCo3).
Step-by-step explanation:
In fact, this mineral is present in many different types of organisms among which are both animals and plants, such as in the shell of some mollusk and the exoskeleton of corals, and it is also a component in the eggshell of reptiles. In the case of plants, it forms the exoskeleton of some algae such as rhodophytes (red algae).