9 some scientists actually consider the exosphere as part of outer space as there is such a gradual and fuzzy distinction between the density of molecules in the very upper reaches of the atmosphere and lower reaches of space
Notice that graphite, commonly seen in pencil lead, and diamonds. have the same chemical formula. Minerals with the same chemical formula but. different crystal structures are called polymorphs. These minerals have different. types of chemical bonds and, thus, different crystal forms. If a substance fails any part of this definition, it is not a mineral. For example, table sugar, an organic compound formed by biological plant activity, fits all. facets of the definition except the inorganic part.
â¢Minerals have a chemical composition that allows for some variation: âMost minerals are compounds âCan be expressed as a chemical formula â¢Example: quartz = SiO 2 âComposition may vary slightly if certain elements substitute for others â¢Substituting elements about the same size will not change the crystalline structure of the mineral