Mineralogy, Mineral Formation, Coal, and Petroleum

Vocabulary practice flashcards covering rock-forming minerals, physical and chemical properties, garnet classifications, mineral formation mechanisms, and fossil fuels from the CE 212 lecture.

Augite

The most common pyroxene mineral (clinopyroxene group) with a chemical composition of $(Ca,Na)(Mg,Fe,Al)(Si,Al)_2O_6$, found in mafic and intermediate igneous rocks such as basalt, gabbro, andesite, and diorite.

Biotite

A large group of black mica sheet silicate minerals commonly found in igneous and metamorphic rocks, featuring perfect cleavage and flexible thin sheets.

Muscovite

The most common mineral of the mica family, present in igneous, metamorphic, and sedimentary rocks, known for splitting into thin, elastic, colorless transparent sheets with a pearly to vitreous luster.

Muscovy Glass

Thin transparent sheets of muscovite mica mined near Moscow, Russia, in the 1700s and historically used as window panes, inspiring the name 'muscovite'.

Calcite

A ubiquitous rock-forming carbonate mineral with the chemical formula $\text{CaCO}_3$, serving as the principal constituent of limestone and marble.

Calcite Physical Properties Table

A summary of calcite's diagnostic traits, including trigonal crystal system, Mohs hardness of $3$, specific gravity of $2.7$, perfect rhombohedral cleavage in three directions, and weak effervescence in dilute $\text{HCl}$ in powdered form.

Garnet Group

A large group of rock-forming silicate minerals sharing a common crystal structure and general chemical formula $X_3Y_2(\text{SiO}_4)_3$, formed mainly during regional metamorphism of aluminum-rich sedimentary rocks.

Almandine

An iron-aluminum garnet mineral with formula $\text{Fe}_3\text{Al}_2(\text{SiO}_4)_3$, specific gravity of $4.20$, Mohs hardness of $7\text{--}7.5$, and red to brown color.

Pyrope

A magnesium-aluminum garnet mineral with formula $\text{Mg}_3\text{Al}_2(\text{SiO}_4)_3$, specific gravity of $3.56$, Mohs hardness of $7\text{--}7.5$, and red to purple color.

Spessartine

A manganese-aluminum garnet mineral with formula $\text{Mn}_3\text{Al}_2(\text{SiO}_4)_3$, specific gravity of $4.18$, Mohs hardness of $6.5\text{--}7.5$, and orange to red to brown color.

Andradite

A calcium-iron garnet mineral with formula $\text{Ca}_3\text{Fe}_2(\text{SiO}_4)_3$, specific gravity of $3.90$, Mohs hardness of $6.5\text{--}7$, and green, yellow, or black color.

Grossular

A calcium-aluminum garnet mineral with formula $\text{Ca}_3\text{Al}_2(\text{SiO}_4)_3$, specific gravity of $3.57$, Mohs hardness of $6.5\text{--}7.5$, and green, yellow, red, pink, or clear color.

Uvarovite

A calcium-chromium garnet mineral with formula $\text{Ca}_3\text{Cr}_2(\text{SiO}_4)_3$, specific gravity of $3.85$, Mohs hardness of $6.5\text{--}7$, and green color.

Garnet Minerals Chart

A chart detailing six key species in the garnet group (Almandine, Pyrope, Spessartine, Andradite, Grossular, Uvarovite) along with their specific formulas, densities, hardness values, and colors.

Magma

Molten rock mixture inside Earth that can exceed $1000^\text{o}\text{C}$ and cools slowly, providing mineral crystals time to grow large.

Lava

Molten rock erupted onto Earth's surface that cools rapidly, preventing mineral crystals from growing large.

Granite Mineral Composition

An intrusive igneous rock containing quartz (clear), plagioclase feldspar (shiny white), potassium feldspar (pink), and biotite (black).

Precipitate

Solid mineral particles formed when water evaporates or when dissolved mineral concentration exceeds saturation limits, causing particles to combine and settle.

Tufa Towers

Towers composed of mineral precipitates formed when calcium-rich spring water at the bottom of Mono Lake bubbles up into the alkaline lake.

Vein

A mineral deposit formed when dissolved minerals in hot underground water precipitate inside cracks and open spaces within rocks as the water cools.

Geode

A hollow rock cavity lined with large mineral crystals, such as amethyst, formed by precipitation from mineral-rich underground hot water.

Peat

Partially decayed plant matter accumulated in swamps and bogs; an early stage prior to coal that possesses low heat content.

Coal

A readily combustible rock containing more than $50$% carbon by weight, formed from decomposed ancient plant matter subjected to geological heat and pressure.

Lignite

Brown coal characterized by low heat content, low sulfur content, and limited regional supply.

Bituminous Coal

Soft coal extensively used as fuel due to its high heat content and large supplies, typically featuring a high sulfur content.

Anthracite

Hard coal highly prized as a fuel because of its high heat content and low sulfur content, though supplies are limited in most areas.

Coal Formation Rank

The developmental sequence from peat to lignite, bituminous coal, and anthracite, marked by increasing heat, pressure, and carbon content alongside decreasing moisture content.

Petroleum

A liquid fossil fuel (crude oil) formed by the subterranean organic decomposition of ancient plant and aquatic life, composed mainly of hydrocarbons and sulfur.