Lesson 2.1: Minerals

mineral

It is defined as a naturally-occurring, inorganic solid with a definite chemical composition and an ordered internal structure.

naturally-occurring, inorganic, solid, definite chemical composition, ordered internal structure

What are the general characteristics of minerals?

naturally-occurring

Minerals exist naturally. Steel and synthetic diamonds are created artificially, and therefore, are not minerals.

Inorganic

Minerals are limited to substances formed through inorganic processes, and exclude materials derived from living organisms which involved organic processes.

mineraloids

Substances that fulfill all the requirements but do not have an ordered internal structure

Silicates

These are composed primarily of silicon-oxygen tetrahedrons. They are the major rock-forming minerals, including olivine and quartz.

Oxides

They consist of metal cations bonded to oxygen anions. Common _____ minerals are magnetite and hematite.

Sulfides

They consist of metal cation bonded to sulfide. They are common ore minerals along with oxides since metals form a high proportion of the mineral. Examples of these are galena and pyrite.

Sulfates

They consist of a metal carbon bonded to the SO2−4 anionic group. They usually precipitate out of water near Earth’s surface. An example of this is gypsum.

Halides

They are composed of a halogen ion, such as chlorine or fluorine, which forms halite or rock salt, and fluorine.

Carbonates

They are characterized by the presence of carbonic ion which bonds elements such as calcium or magnesium to form calcite or dolomite.

Native metals

They consist of a single metal such as copper and gold.

Crystal structure

It is dependent on the chemical composition of the mineral.

triclinic, monoclinic, orthorhombic, tetragonal, hexagonal, isometric

What are the six crystal systems used in grouping minerals based on structure?

Dana classification

Systematic method used for identifying minerals

habit

The outward appearance of the mineral’s crystal form

cleavage

The tendency of a mineral to break along planes of weakness

conchoidal fracture

minerals that do not have cleavage will fracture either in an irregular manner

luster

It describes the appearance of light as it is reflected off its surface.

Streak

color of a mineral in its powdered form.

hardness of a mineral

It is a measurement of the strength of the chemical bonds in its structure. It can be measured by scratching it with another mineral or a reference material with known hardness.

Mohs scale of hardness

It is a relative measure of hardness using common materials and standard minerals to represent a specific hardness value.

Specific gravity

It is a measure of the density of a mineral. It is the weight of a mineral relative to the weight of an equal volume of water.