A: According to BBC, an endoskeleton is a bone structure located in the interior of an animal, and an exoskeleton is a bone structure located on the exterior of an animal. Each type of skeleton has unique advantages and disadvantages in helping the animal survive.
Minerals made of only one element are called NATIVE minerals (i.e., silver, gold, mercury, copper). Minerals composed of compounds are simply referred to as minerals (i.e., quartz, which is made up on silicon and oxygen).
Minerals that are not pure elements are made of compounds. For example, the mineral quartz is made of the compound silicon dioxide, or SiO 2. This compound has one atom of the element silicon for every two atoms of the element oxygen.When a mineral has a different chemical formula, it is a different mineral.or example, the mineral hematite has two iron atoms for every three oxygen atoms, while the mineral magnetite has three iron atoms for every four oxygen atoms. Many minerals contain more complex chemical compounds that are made of several elements.