Which of the following are characteristics of a mineral (select all that apply) ? A. It possesses a specific crystalline structure. B. It is naturally formed. C. It possesses a specific chemical composition that varies only within certain limits. D. It is a solid.

Answer: Option (A), (B), (C) and (D)

Explanation: A mineral is defined as a naturally arising, inorganic solid, that contains a precise chemical composition and defined crystal structure. Minerals combines to form rocks. A rock contains various minerals which are formed at different pressure and temperature condition. For example, olivine, quartz, gypsum and calcite.

Minerals are often classified as oxide minerals, carbonate minerals, silicate minerals, sulfate and sulfide minerals.

Thus, all the given options are a characteristics of a mineral.