Any visibly granular, igneous rock consisting mostly of feldspars and quartz accompanied by one or more dark minerals. (ASTM C1528) The texture is typically homogeneous but may be gneissic or porphyritic. Some dark granular igneous rocks, though not geologically granite, are included in the definition. (ASTM C119)
A sedimentary rock composed principally of calcium carbonate (the mineral calcite) or the double carbonate of calcium and magnesium (the mineral dolomite), or a mixture of the two. (ASTM C1528) Recrystallized limestone, compact microcrystalline limestone, and travertine that are capable of taking a polish are also included in the category commercial marble and may be sold as either limestone or marble. (ASTM C119)
A metamorphic rock resulting from the recrystallization of limestone, comprising crystallized grains of calcite (calcium carbonate) or dolomite (calcium magnesium carbonate), or both. Also, rocks ranging from pure carbonate to those containing very little carbonate, yet having compositions and textures that permit them to be polished. (ASTM C1528) All stone here defined as marble must be capable of taking a
polish. (ASTM C119)
A microcrystalline, metamorphic rock commonly derived from shale, composed mostly of micas, chlorite, and quartz. (ASTM C1528) The micaceous minerals have a subparallel orientation and thus impart strong cleavage to the rock which allows the latter to be split into thin but tough sheets. (ASTM C119) Includes shale, a laminated, indurated rock which is over two-thirds clay-sized minerals. Shales progressively grade into slate. (ASTM C119)
There are a number of stones that are infrequently used. Some semiprecious stones such as jade are cut and used as dimension stone. They would most commonly be used as a contrast or accent in connection with other dimension stone. (ASTM C119) Includes alabaster, greenstone, schist, serpentine (commercial definition), soapstone, and sometimes travertine.