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Pertaining to, having the nature of, fire; containing fire; resembling fire; as, an igneous appearance.

be tried with shoots of vines and roots of red roses; for it may be they, being of a moreligneous nature, will incorporate with the tree itself. Bacon. Ligneous marble, wood coated or prepared so as to resemble marble.

Pertaining to, or designating, the acid liquid obtained in the distillation of wood, consisting essentially of impure acetic acid.

Half or partially ligneous, as a stem partly woody and partly herbaceous.

tion a silicate of alumina and soda. It is a common constituent of granite and of various igneous rocks. See Feldspar.

rally separated in the record by unconformities. Algonkian rocks are both sedimentary and igneous. Although fossils are rare, life certainly existed in this period. -- n.

feldspar family, commonly occurring in small glassy crystals, also a constituent of some igneous rocks. It is a lime feldspar. See Feldspar.

A granular igneous rock composed almost exclusively of a soda- lime feldspar, usually labradorite.

ch are deposited from water and lie in strata, as opposed to volcanic rocks, which are of igneous origin; -- called also sedimentary rocks.

A variety of pyroxene, usually of a black or dark green color, occurring in igneous rocks, such as basalt; -- also used instead of the general term pyroxene.

A rock of igneous origin, consisting of augite and triclinic feldspar, with grains of magnetic or titanic iron, and also bottle- green particles of olivine frequently disseminated.

An igneous rock of feldspathic composition, lamellar in structure, and clinking under the hammer. See Phonolite.

a cup joint, showing a concave surface above. This structure is characteristic of certain igneous rocks, as basalt, and is due to contraction in cooling.

A basic, dark-colored, holocrystalline, igneous rock, consisting essentially of a triclinic feldspar and pyroxene with magnetic iron; -- often limited to rocks pretertiary in age. It includes part of what was early called greenstone.

A dark green or bronze-colored laminated variety of pyroxene, common in certain igneous rocks.

A wall-like mass of mineral matter, usually an intrusion of igneous rocks, filling up rents or fissures in the original strata.

An igneous, crystalline in structure, consisting essentially of a triclinic feldspar and hornblende. It includes part of what was called greenstone.

An igneous rock composed of orthoclase, elæolite, and sodalite.

A dark-colored, basic, igneous rock, composed essentially of pyroxene and a triclinic feldspar with magnetic iron. By many authors it is considered equivalent to a coarse-grained basalt.

Produced by eruption; as, eruptive rocks, such as the igneous or volcanic.