L03 - Minerals and the Rock Cycle

What is the definition of a mineral?,

A mineral is a naturally occurring, inorganic solid with an orderly internal structure, characteristic chemical composition, crystal form, and physical properties.

What are the five criteria that define a mineral?,

1. Naturally occurring

2. Inorganic

3. Solid

4. Orderly internal structure (crystalline)

5. Set chemical composition

Is ice considered a mineral? Why or why not?,

Yes, ice is a mineral because it meets all five criteria: naturally occurring, inorganic, solid, crystalline structure, and defined chemical composition.

What are the four major ways minerals form?,

1. Cooling and crystallizing from magma or lava

2. Precipitation from a fluid

3. Chemical changes due to metamorphism

4. Precipitation from biogenic activity (biomineralization)

How does cooling rate affect crystal size in igneous minerals?,Fast cooling produces small crystals; slow cooling allows larger crystals to form.

How are minerals categorized into groups?,

Minerals are grouped based on their anions (negatively charged ions), which influence their properties.

What are the major mineral groups and their anions?,

Silicates: SiO₄⁴⁻

Carbonates: CO₃²⁻

Sulfates: SO₄²⁻

Sulfides: S²⁻

Oxides: O²⁻

Native elements: single elements like gold or carbon

What is a silica tetrahedron?,

A silica tetrahedron is the basic building block of silicate minerals, consisting of one silicon atom bonded to four oxygen atoms.

Why are minerals important in engineering?,

Minerals affect material properties like strength, durability, and reactivity. For example, sheet silicates weather easily and can form clays that absorb water, impacting soil stability.

What are some engineering concerns with carbonate minerals?,

Carbonates dissolve in slightly acidic rainwater, leading to sinkholes and karst topography, which can compromise structural foundations.

What is acid mine drainage and why is it a concern?,

Acid mine drainage occurs when sulfide minerals oxidize, lowering pH and causing environmental damage, especially near old mines.

Can two minerals have the same chemical composition but different properties?,

Yes. For example, graphite and diamond are both made of carbon but have different structures and properties.

What is the definition of a rock?,A rock is an agglomeration of minerals.

What are the three main types of rock?,

1. Igneous - crystallized from melted material

2. Sedimentary - formed from deposition of weathered material

3. Metamorphic - altered by heat, pressure, fluids, and time

Can rocks change from one type to another?,

Yes, through the rock cycle. For example, igneous rocks can become sedimentary or metamorphic, and vice versa.

What is karst topography?,

A landscape formed by the dissolution of carbonate rocks, featuring caves, sinkholes, and springs.