17. a is defined as a naturally occurring inorganic solid with a specific chemical composition and usually a…

17. a is defined as a naturally occurring inorganic solid with a specific chemical composition and usually a crystalline structure. 18. rocks are classified into three main groups: , , and .

17. a is defined as a naturally occurring inorganic solid with a specific chemical composition and usually a crystalline structure. 18. rocks are classified into three main groups: , , and .

Answer

Brief Explanations:

  1. By the standard geological - mineral definition, a mineral is a naturally occurring inorganic solid with a specific chemical composition and usually a crystalline structure.
  2. Geologically, rocks are classified into igneous, sedimentary, and metamorphic rocks based on their formation processes.

Answer:

  1. Mineral
  2. Igneous, Sedimentary, Metamorphic