Crystal structure depends on the conditions under which the mineral forms. Polymorphs are minerals with the same chemical composition but different crystal structures. Liquids and gases do not have an ordered crystal structure and are not minerals.

The atoms in a mineral are arranged in an organised ‘atomic structure’. They connect together to form molecules, and the molecules stack together in a regular pattern to form a crystal. The shape of a crystal depends on the way the molecules are stacked up inside it.

The atomic structure of all minerals determines their physical properties, as illustrated by the large block of mica, and its well-developed cleavage. However, the atoms forming the crystal structure of minerals are often less closely packed, or have weaker bonds, in some directions than in others.

All minerals have a specific chemical composition. The mineral silver is made up of only silver atoms and diamond is made only of carbon atoms, but most minerals are made up of chemical compounds. Each mineral has its own chemical formula.

Wood- is not considered a mineral because its an organic material. Based on the definition of mineral, which of the following materials are not classified as minerals and why, gold, water, synthetic diamonds, ice, and wood. In contrast of minerals rocks are loosely defined.

Oxygen is not a mineral because oxygen atoms by them- selves do not have a crystalline structure. Teeth are not minerals because they are living parts of your body. Ice is considered to be a mineral because it is a solid, it is a non- living material, it is formed in nature, and it has a definite crystalline structure.

Most minerals can be characterized and classified by their unique physical properties: hardness, luster, color, streak, specific gravity, cleavage, fracture, and tenacity.