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e, later to the rock called euphotide, and now generally used for a coarsely crystalline, igneous rock consisting of lamellar pyroxene (diallage) and labradorite, with sometimes chrysolite (olivine gabbro).

A name formerly applied rather loosely to certain dark-colored igneous rocks, including diorite, diabase, etc.

A mass of igneous rock intruded between sedimentary beds and resulting in a mammiform bulging of the overlying strata. -- Lac`co*lit"ic, a.

Having a slender elongated form, like a lath; -- said of the feldspar of certain igneous rocks, as diabase, as seen in microscopic sections.

A nearly opaque white mineral, in part identical with titanite, observed in some igneous rocks as the result of the alteration of titanic iron.

An igneous rock consisting largely of chrysolite, with pyroxene and picotite (a variety of spinel containing chromium).

To convert into wood or into a ligneous substance.

Ligneous. [R.] Evelyn.

hemical composition and usually a distinct crystalline form. Rocks, except certain glassy igneous forms, are either simple minerals or aggregates of minerals.

A compact, feldspathic, igneous rock containing nephelite, haüynite, etc. Thin slabs give a ringing sound when struck; -- called also clinkstone.

A dark green igneous rock, consisting largely of chrysolite, with hornblende, augite, biotite, etc.

An igneous rock of semiglassy nature, having a luster like pitch.

Of, pertaining to, or designating, the system of the Plutonists; igneous; as, the Plutonic theory. Plutonic action (Geol.), the influence of volcanic heat and other subterranean forces under pressure. -- Plutonic rocks (Geol.), granite, porphyry, and some other igneous rocks, supposed to have consolidated from a melte…

early advanced in geology, that the successive rocks of the earth''s crust were formed by igneous fusion; -- opposed to the Neptunian theory.

One who adopts the geological theory of igneous fusion; a Plutonian. See Plutonism.

Produced by fire; igneous. Mantell. .

A crude acetate produced by treating pyroligneous acid with a metal or basic compound; as, pyrolignite of iron (iron liquor).

Same as Pyroligneous.

es alumina and iron. Pyroxene is an essential constituent of many rocks, especially basic igneous rocks, as basalt, gabbro, etc.

A quartzose trachyte, an igneous rock often showing a fluidal structure. -- Rhy`o*lit"ic, a.