Introduction to Inorganic Materials: Metals, Ceramics, Minerals, Rocks, and Mortars

Vocabulary practice flashcards covering crystalline structure, metallic alloys, corrosion, silicate ceramics, mineralogy, petrology, and binding mortars.

Ore

A natural earth material consisting of one or more minerals from which a metal can be extracted after processing.

Mineral

Any naturally occurring inorganic compound or chemical element found in the earth that constitutes a component of rocks.

Rock

Natural solid material composed of minerals that makes up the solid crust of the Earth.

Crystalline Material

A solid material in which constituent atoms, ions, or molecules are arranged in an ordered, repeating long-range spatial pattern.

Unit Cell

The small repeating structural unit of atoms, ions, or molecules that forms a three-dimensional crystal lattice pattern.

Body-Centered Cubic (BCC) Structure

A crystal unit cell where atoms are located at the 8 cube corners plus 1 atom at the center, having $N = 2$ atoms per cell, cell edge $a = \frac{4R}{\sqrt{3}}$, coordination number $8$, and $APF = 0.68$.

Face-Centered Cubic (FCC) Structure

A crystal unit cell with atoms at the 8 corners and centers of 6 faces, having $N = 4$ atoms per cell, cell edge $a = 2R\sqrt{2}$, coordination number $12$, and $APF = 0.74$.

Hexagonal Close-Packed (HCP) Structure

A crystal unit cell with hexagonal top and bottom faces (containing 6 corner atoms and 1 center atom each) plus 3 intermediate atoms, having $N = 6$ atoms per unit cell, coordination number $12$, and $APF = 0.74$.

Coordination Number

The number of immediate neighboring atoms with which a given atom is in direct contact within a crystal lattice.

Atomic Packing Factor (APF)

The ratio of the total volume of solid spheres occupied by atoms in a unit cell to the total volume of the unit cell.

Theoretical Density Formula

The calculated density of a crystalline solid given by $\rho = \frac{N \times AW}{V_c \times N_A}$, where $N$ is the number of atoms per cell, $AW$ is atomic weight, $V_c$ is cell volume, and $N_A$ is Avogadro's number.

Polymorphism

The ability of a solid material to exist in more than one crystal structure depending on ambient temperature and pressure.

Allotropy

The occurrence of polymorphism in elemental solids, such as elemental carbon existing as graphite or diamond.

Metallic Glass

An amorphous metal alloy produced by ultra-rapid cooling of molten metal, preventing crystallization and freezing the material in a vitreous state.

Liquid Crystal

A fluid state of matter that flows like a liquid while maintaining positional or orientational order among its molecules similar to a solid crystal.

Cathodic Protection

A method used to prevent metal corrosion by attaching an external sacrificial anode or applying an external electrical current to render the metal surface cathodic.

Bronze

A copper-tin alloy ($Cu\text{-}Sn$) containing up to $10\%$ Sn by weight, offering improved strength, hardness, and corrosion resistance over pure copper.

Brass

An alloy composed of copper and zinc ($Cu\text{-}Zn$) containing up to $50\%$ Zn by weight.

Steel

An iron-carbon alloy ($Fe\text{-}C$) with carbon content typically up to $2\%$ by weight.

Cast Iron

An iron-carbon alloy ($Fe\text{-}C$) containing more than $2\%$ carbon (typically $3\text{-}5\%$), which is characteristically brittle.

Stainless Steel

An iron-carbon-chromium alloy ($Fe\text{-}C\text{-}Cr$) containing more than $11\%$ chromium by weight, providing high corrosion resistance.

Lead (Pb) Sheathing

A soft metal coating ($16\,GPa$ modulus of elasticity) used around iron structural clamps in ancient architecture to absorb thermal and corrosion expansion stresses.

Carat

A unit measuring gold alloy purity expressed in parts per 24 by weight, where 24 carats represents pure gold ($100\%$ weight basis).

Ceramics

Inorganic non-metallic compounds (often oxides, nitrides, carbides, or sulfides) formed between metallic and non-metallic elements, known for poor thermal/electrical conductivity and high brittleness.

Silica

Silicon dioxide ($SiO_2$), a silicate ceramic existing in polymorphic crystalline structures including quartz, cristobalite, and tridymite.

Glass

An amorphous silicate ceramic produced by melting quartz sand ($SiO_2 \approx 70\%$) together with sodium carbonate ($Na_2CO_3 \approx 15\%$) and other metal oxides.

Hydroxyapatite

A calcium phosphate mineral with chemical formula $Ca_5(PO_4)_3(OH)$, serving as the chief structural constituent of bones and tooth enamel.

Fluorapatite

A mineral with formula $Ca_5(PO_4)_3F$ formed during dental fluoridation that exhibits higher acid corrosion resistance than hydroxyapatite.

Kaolinite

A hydrated aluminum silicate mineral with chemical formula $Al_2O_3 \cdot 2SiO_2 \cdot 2H_2O$ that forms plastic clay when mixed with water.

Igneous Rocks

Rocks formed from the cooling and solidification of molten magma, classified into volcanic (e.g., obsidian, basalt) and plutonic (e.g., granite) types.

Sedimentary Rocks

Rocks formed through the precipitation and consolidation of mineral sediments deposited in water, such as limestone and sandstone.

Metamorphic Rocks

Rocks formed by the transformation of pre-existing rocks under high temperature and pressure, such as marble and slate.

Calcite

The most stable trigonal crystalline polymorph of natural calcium carbonate ($CaCO_3$).

Aragonite

An orthorhombic crystalline form of calcium carbonate ($CaCO_3$) found in marine shells.

Vaterite

The most unstable hexagonal crystalline polymorph of calcium carbonate ($CaCO_3$) found in nature.

Dolomite

A calcium magnesium carbonate mineral with chemical formula $CaMg(CO_3)_2$.

Huntite

A magnesium calcium carbonate mineral with chemical formula $Mg_3Ca(CO_3)_4$, historically used as a white pigment in Macedonian and Egyptian tomb paintings.

Limestone

A widespread sedimentary rock composed primarily of the mineral calcite ($CaCO_3$).

Marble

A metamorphic rock formed from the metamorphism of limestone or dolomite rocks.

Gypsum

A hydrated calcium sulfate mineral with chemical formula $CaSO_4 \cdot 2H_2O$.

Quartz

A crystalline form of silicon dioxide ($SiO_2$) and a major mineral component of all rock classes.

Azurite

A copper carbonate mineral with formula $2CuCO_3 \cdot Cu(OH)_2$.

Obsidian

A dark, natural volcanic glass rock consisting mainly of amorphous $SiO_2$ produced by rapid cooling of lava.

Mortar

A workable building paste created by combining a fine binder (such as lime or cement), an aggregate (usually sand), and water.

Air Lime Mortar

A mortar binder that hardens in the presence of air through carbonation: $Ca(OH)_2 + CO_2 \rightarrow CaCO_3 + H_2O$.

Hydraulic Lime Mortar

A mortar containing reactive oxides ($Al_2O_3$, $SiO_2$, $Fe_2O_3$) that allow setting underwater or without air via reactions such as $Ca(OH)_2 + SiO_2 \rightarrow CaSiO_3 + H_2O$.

Quicklime

Anhydrous calcium oxide ($CaO$) produced by high-temperature calcination ($> 1000\,^\circ\text{C}$) of limestone: $CaCO_3 \rightarrow CaO + CO_2$.

Slaked Lime

Calcium hydroxide ($Ca(OH)_2$) produced by the exothermic slaking reaction of quicklime ($CaO$) with water: $CaO + H_2O \rightarrow Ca(OH)_2$.

Portland Cement

A common hydraulic cement prepared by calcining and grinding limestone, clay, and iron minerals, composed of major phases $3CaO \cdot SiO_2$, $2CaO \cdot SiO_2$, $3CaO \cdot Al_2O_3$, and $4CaO \cdot Al_2O_3 \cdot Fe_2O_3$.

Reinforced Concrete

A high-strength composite material formed by embedding steel rebar within concrete to withstand compressive and tensile forces.