Mineralogy

Covalent

Atoms share electrons to achieve a full outer shell → strong and directional

Ionic

Electrons are transferred between atoms, forming positive and negative ions that attract each other

Metallic

Metal atoms share a "sea" of free-moving electrons, creating conductivity and malleability

Hydrogen

Weak attraction between a hydrogen atom (bonded to N, O, or F) and a nearby electronegative atom

Van der Waals

Weak, temporary attractions between molecules due to fluctuating electron distributions

3 process of silicate formation

Magma crystallization, metamorphic reaction, water reaction

4 process of non-silicate formation

Hydrothermal process, biogenic formation, evaporation, hydrolitic weathering

Major cations in water

Ca²⁺, Mg²⁺, Na⁺, K⁺

Major anions in water

HCO₃^-, SO₄^2-, Cl^-

3 types of geochemical reactions that alter element composition in water

Dissolution → Mineral dissolves and release elements to the solution

Precipitation → A mineral precipitate (forms) and removes elements from the solution

Absorption → During interaction elements can be exchanged between fluids and mineral surfaces by absorption

reactions rates of different rock forming minerals (from less reactive to the most reactive)

Quartz, Muscovite, Andesine, Dolomite, Calcite

What controls dissolution rates

Crystal structure and chemical composition of the mineral, composition of the fluid, temperature, surface of the mineral ,Transport of reactants and products to and from reacting surfaces

Types of water pollution

Oxigen-demanding waste, pathogens, nutrients, toxic substances, microplastics

Source of each water pollution

Oxygen → anything that introduces organic matter into the water (dead body, dead plants, animal manure…)

Pathogens → contaminated animal waste

Nutrients → fertilizer, sewage, detergents…

Toxic substances → mining, industrial use, waterproof clothing, non-sticks pans

Microplastics → degraded plastic waste, synthetic fabric washing, tire wear, cosmetics…

Major human activities that impact biogeochemical process

Mining, fossil fuel burning, construction activities, biomass burning, human apportionment of terrestrial primary productivity, industrial activities…

Impacts of climate change

Rising global temperatures, melting ice caps and glaciers, sea level rise, extreme weather events, ocean acidification, disruption of ecosystems, water scarcity, economic consequences…

Risks of climate change as a function of increased temperature increments

1.5°C: Increased extreme weather, coral bleaching, sea-level rise, biodiversity loss, and agricultural impacts.

2°C: More severe weather events, significant ice melt, water stress, and declining agricultural productivity.

3°C: Widespread heat stress, major sea-level rise, ecosystem collapse, water scarcity, and agricultural collapse.

4°C: Severe heatwaves, massive coastal displacement, food crisis, and increased conflicts.

5°C+: Ecosystem breakdown, catastrophic sea-level rise, global suffering, and irreversible climate damage.

Solubility of a mineral

Positive cation is attracted to the negative end of the water molecule (oxygen), negative anion is attracted to the positive end of the water molecule (hydrogen) → Covalent and Metallic are Insoluble

Silicate polymerisation

Island, double island, ring, chain, sheet, tecto/framework

Island

Isolated SiO4 tetrahedra → Si:O = 1:4 → Olivine

Double Island

Si:O = 1:3.5 → 1 bridging Oxygen

Ring

Si:O = 1:3 → two bridging oxygen → each tetrahedra is connected to other two forming a ring

Chain

Single → Si:O = 1:3 → 2 bridging oxygen → each is connected to other two but without forming a ring

Double → Si:O = 2:5.5 → 2 or 3 bridging Oxygen

Sheet

Si:O = 1:2.5 → 3 bridging oxygen

Tecto Framework

Si:O = 1:2 → 4 bridging Oxygen → Quartz

Magma Crystallisation

The crystallization of magma occurs as it cools, forming different minerals at specific temperatures based on their melting points → Olivine

Metamorphic reaction

Metamorphic reactions occur when rocks are subjected to high pressure and temperature, causing minerals to recrystallize into stable forms for the new conditions → Garnet, Kyanite

Water Reaction

Hydrothermal alteration occurs when water reacts with a rock's minerals, transforming them into new hydrated minerals

Definition and importance of Mineral wheatering

Weathering = the natural physical and/or chemical decomposition of rocks at or near the Earth's surface (focus on chemical) → Helps regulate climate over geological timescales, provides nutrient that supports life, generation of soil, buffers change in PH in soil → Weathering liberates the ingredients needed to produce and sustain all biogeochemical processes

Biogeochemical cycles

Describes the processes by which an element or molecule is continuously cycled amongst different components (called reservoirs) of an environment

Also called “element cycles” or in the case of nutrients: “nutrient cycles”

Driven by interactions between the Earth’s spheres

Human activities alter these cycles (e.g., pollution)

Acid mine drainage

Oxidative dissolution of sulfide minerals (particularly pyrite [FeS2]) in mine wastes from some metal mines and coal mines generates highly acidic, toxic-metal rich waste waters → hazardous metals and acid can be released in the surroundings

Cations

elements giving up one or more electrons (+ charge)

Anions

elements accepting one or more electrons (- charge)