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Glossary of Geologic and Architectural Terms

Antefix - an ornament along the edge of a roof, often shaped like a shell or shield
Baluster - a post or support for a handrail
Balustrade - a rail and row of supporting posts, especially along a stair or porch
Bronze - a metal alloy of copper and tin; although brown when fresh, it weathers to a more commonly seen green color
Calcite - a mineral composed of calcium carbonate: CaCO3
Column Capital - The top portion of a column. There are three main types; from least ornate to most ornate, they are Doric, Ionic, and Corinthian
Diabase - a dark-gray to black, fine-textured igneous rock, composed of the minerals feldspar and pyroxene
Feldspar - a common mineral composed of silica (Si), aluminum (Al), and calcium (Ca), potassium (K), or sodium (Na): CaAl2Si2O8,KAlSi3O8,NaAlSi3O8
Fossil - remains or trace of a plant or animal preserved in a rock from some past, prehistoric time
Granite - a light or speckled, coarse-grained igneous rock composed of quartz, feldspar, and mica
Guttae - small, drop-like rounded ornaments under a roof overhang
Gypsum - a mineral composed of hydrated calcium sulfate: CaSO4.2H2O
Igneous - formed from melted or partially molten rock
Inclusion - a mineral phase that is distinct (in composition or appearance) from the main mineral components of a rock
Limestone - a sedimentary rock, chiefly composed of calcium carbonate; formed from the shells of marine animals
Marble - a metamorphic rock, chiefly composed of calcium carbonate
Metamorphic - changed; usually by heat or pressure to a different form but the same composition
Mica - a silicate mineral that forms sheets or layers and contains aluminum, hydroxyl, and alkali ions: K2Al4Si6Al2O20(OH,F)4, K2(Mg,Fe)6Si6Al2O20(OH,F)4
Mineral - a naturally occurring inorganic substance with an ordered structure; rocks are made of one or more minerals
Portico - a porch, with a roof supported by columns
Pyrite - a mineral ("fool's gold") composed of iron sulfide: FeS2
Pyroxene - a silicate mineral containing two metal oxides: CaMgSi2O6,CaFeSi2O6,(Mg,Fe)SiO3
Quartz - a mineral composed of silicon dioxide, or silica: SiO2
Sandstone - a sedimentary rock composed chiefly of quartz grains
Sedimentary - formed from particles that were transported by water or wind and deposited in layers
Volute - a scroll-like ornament on an Ionic column capital

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Last modified 07.21.97