In order for a substance to be a mineral, it must have ALL five of the following characteristics:
In order for a substance to be a mineral, it must have ALL five of the following characteristics:
a. Naturally Occurring – it must be formed by processes that occur in the natural world.
I. Example: Quartz forms naturally as magma cools and hardens deep beneath the Earth’s surface.
ii. Plastic, brick, glass, steel are NOT minerals because they are man-made.
Inorganic– Cannot form from materials that were once part of a living thing.
i. Example: Coal is NOT a mineral because it forms from the remains of plants that lived long ago.
c. Solid (NOT liquid). Definite volume and shape; particles are tightly packed together so they cannot move like they can in a liquid.
i. Water is NOT a mineral in its liquid form, but can become a mineral when it cools and hardens.
Crystal structure – the particles in the mineral line up in a pattern that repeats over and over.
i. The repeating pattern forms a solid called a crystal
ii. A crystal has flat sides called faces that meet at sharp edges and corners.
e. Definite chemical composition – minerals always contains certain elements in definite proportions.
i. Minerals can be either elements (a single substance) or a compound (a combination of 2 or more elements).
ii. Most minerals chemically are compounds, because they are made of two or more elements.
Hardness-A mineral’s ability to scratch or be scratched by another mineral; Mohs Hardness scale; Ranked 1-10; Determined with a scratch test-minerals can only scratch a softer mineral
Color-characteristic property of some minerals; Not always reliable: i.e. quartz in different colors; physically observed by sight
Streak-The color of a mineral’s powder; a mineral’s color may vary, but its streak does not and they are often different; Rub a mineral against a piece of unglazed tile and visually observe powder
Density-Mass per unit volume; Calculated by density=mass/volume; Mass determined using a balance and Volume determined with water displacement
Crystal System-Crystal shapes put into six groups based on number and angle of crystal faces; Visually observed using microscopes if too small to observe with the naked eye
Luster-How a mineral reflects light from its surface; Minerals containing metal are usually shiny-Terms used: earthy, waxy, pearly, glassy; visually observed
By evaporation – When minerals are dissolved in water, and the water evaporates, the minerals that are left behind will form crystals
Example: Slow evaporation of seawater leaves behind minerals such as halite and calcite
By the cooling of a hot water solution:
Magma heats water underground Minerals dissolve in hot water to form solutions Solutions follow cracks in earth’s crust called veins As solution cools, elements crystallize to form a mineral.
Example: Pure Silver can crystallize in veins from a hot water solution.
Minerals are formed by crystallization- process where atoms join to form a crystal structure
Crystallization of magma or lava:
Crystallization of materials dissolved in water
Formed when magma cools inside crust or when lava cools and hardens on the surface:
Slow cooling deep underground forms large crystals
Fast cooling close to or above the surface forms small crystals
In order for a substance to be a mineral, it must have ALL five of the following characteristics:
a. Naturally Occurring – it must be formed by processes that occur in the natural world.
I. Example: Quartz forms naturally as magma cools and hardens deep beneath the Earth’s surface.
ii. Plastic, brick, glass, steel are NOT minerals because they are man-made.
Inorganic– Cannot form from materials that were once part of a living thing.
i. Example: Coal is NOT a mineral because it forms from the remains of plants that lived long ago.
c. Solid (NOT liquid). Definite volume and shape; particles are tightly packed together so they cannot move like they can in a liquid.
i. Water is NOT a mineral in its liquid form, but can become a mineral when it cools and hardens.
Crystal structure – the particles in the mineral line up in a pattern that repeats over and over.
i. The repeating pattern forms a solid called a crystal
ii. A crystal has flat sides called faces that meet at sharp edges and corners.
e. Definite chemical composition – minerals always contains certain elements in definite proportions.
i. Minerals can be either elements (a single substance) or a compound (a combination of 2 or more elements).
ii. Most minerals chemically are compounds, because they are made of two or more elements.
Hardness-A mineral’s ability to scratch or be scratched by another mineral; Mohs Hardness scale; Ranked 1-10; Determined with a scratch test-minerals can only scratch a softer mineral
Color-characteristic property of some minerals; Not always reliable: i.e. quartz in different colors; physically observed by sight
Streak-The color of a mineral’s powder; a mineral’s color may vary, but its streak does not and they are often different; Rub a mineral against a piece of unglazed tile and visually observe powder
Density-Mass per unit volume; Calculated by density=mass/volume; Mass determined using a balance and Volume determined with water displacement
Crystal System-Crystal shapes put into six groups based on number and angle of crystal faces; Visually observed using microscopes if too small to observe with the naked eye
Luster-How a mineral reflects light from its surface; Minerals containing metal are usually shiny-Terms used: earthy, waxy, pearly, glassy; visually observed
By evaporation – When minerals are dissolved in water, and the water evaporates, the minerals that are left behind will form crystals
Example: Slow evaporation of seawater leaves behind minerals such as halite and calcite
By the cooling of a hot water solution:
Magma heats water underground Minerals dissolve in hot water to form solutions Solutions follow cracks in earth’s crust called veins As solution cools, elements crystallize to form a mineral.
Example: Pure Silver can crystallize in veins from a hot water solution.
Minerals are formed by crystallization- process where atoms join to form a crystal structure
Crystallization of magma or lava:
Crystallization of materials dissolved in water
Formed when magma cools inside crust or when lava cools and hardens on the surface:
Slow cooling deep underground forms large crystals
Fast cooling close to or above the surface forms small crystals