Abrasion, the act of rubbing off. Latin, ab, from; radere, to rub or scrape.

Aggregates, accumulations or masses. Latin, ag, to; grex, gregis, a flock.

Align, to put into line. Latin, ad, to; linea, a line.

Amorphous, without regular form. Greek, a, not; morphe, form.

Annular, in the shape of a ring. Latin, anulus, a ring.

Anticlinal, sloping in opposite directions. Greek, anti, against; klin-ein, to lean.

Aqueous, deposited by water. Latin, aqua, water.

Arenaceous, sandy. Latin, arena, sand.

Argillaceous, containing clay. Greek, argilos, white clay.

Automatic, self-moving. Greek, automatos, self-moving.

Bacteria, germs. Greek, baktron, stick or staff.

Brecciated, composed of conglomerate rock. French, breche, a flint pebble.

Calcareous, containing lime or chalk. Latin, calx, calcis, chalk.

Carbonaceous, composed of carbon. Latin, carbo, coal.

Carboniferous, producing carbon or coal. Latin, carbo, coal; ferre, to bear.

Caulking, pressing a seam or joint to render it tight. Old French, cauquer, to press.

Chronological, relating to time. Greek, chronos, time; logia, a discourse.

Concretionary, grown into one nodular mass. Latin, con, together; crescere, to grow.

Cylindrical, a roller-like body whose ends are equal parallel circles. Greek, kylindros, to roll.

Debris, a mass of rocky fragments. French, briser, to break.

Denudation, act of laying bare. Latin, de, down; nudus, naked.

Detonation, an explosion with a loud noise. Latin, de, down; tonare, to thunder.

Devitrification, loss or diminution of glassy nature. Latin, de, down; vitrum, glass.

Disintegration, act of crushing into pieces. Latin, dis, not; integer, entire.

Dynamic, relating to force. Greek, dynamis, power.

Effusive, pouring forth abundantly. Latin, ef= ex, out; fundere, to

Erratics, transported blocks of stone or boulders. Latin, errare, to wander.

Erosion, act of being eaten away. Latin, e, out; rodere, to gnaw.

Ferruginous, impregnated with iron. Latin, ferrum, iron.

Foliated, consisting of thin plates or leaves. Latin, folium, a leaf.

Friable, apt to crumble. Latin, friare, to crumble.

Hade, the dip or underlie of a fault. A mining term.

Homogeneous, having the same kind of nature. Greek, homos, the same; genos, kind.

Hydrosphere, a watery covering. Greek, hydor, water; sphaira, a sphere.

Igneous, produced by the action of fire. Latin, ignis, fire.

Impermeable, not permitting passage. Latin, in, not; per, through; meare, to pass.

Incineration, the act of reducing to ashes by combustion. Latin, in, in ; cinis, ashes.

Incoherent, not connected. Latin, in, not; con, together; haerere, to stick.

Incombustible, incapable of being burned. Latin, in, not; cornburere, to burn up.

Intrusive, entering without right. Latin, in, into; trudere, to thrust.

Irrespirable, unable to be breathed. Latin, in, not; respirare, to breathe.

Laminated, consisting of overlapping scales or leaves. Latin, lamina, a thin plate.

Lateral, situated on the side. Latin, latus, a side.

Lithosphere, the stony crust of the earth. Greek, lithos, a stone; sphaira, a sphere.

Magma, the molten mass within the earth’s crust. Greek, magma, a soft doughy mass.

Matrix, the stony base in which minerals are found embedded. Latin, mater, a mother.

Medial, belonging to the middle. Latin, medius, the middle.

Metamorphic, applies to changes in rock structure due to heat and pressure. Greek, meta, change; morphe, form.

Nodules, little knots or lumps. Latin, nodus, a knot.

Octahedral, having eight faces. Greek, okto, eight; hedra, a base.

Orthoclase, common type of felspar. Greek, orthos, straight; klasis, a fracture.

Percussive, to strike forcibly. Latin, per, thoroughly; quatere, to shake.

Periphery, the bounding line of a closed figure. Greek, peri, around; pherein, to carry.

Pennules, little feathers. Latin, penna, a feather.

Plagioclase, felspar showing oblique cleavage. Greek, plagios, oblique; klasis, a fracture.

Plutonic, formed by the agency of heat deep down below the earth’s surface. Greek, Pluto, the god of the nether regions.

Radial, shooting out like a ray. Latin, radius, a ray.

Rhomboidal, having the nature of a rhomboid; a quadilateral figure having its sides equal but its angles not right angles. Latin, rhombus, a rhomb; oides, form.

Rotary, turning round like a wheel. Latin, rota, a wheel.

Siliceous, pertaining to silica or flint. Latin, silex, flint.

Stratified, formed in layers or strata. Latin, stratum, sternere, to spread out.

Striated, striped or streaked. Latin, stria, a streak or furrow.

Synclinal, sloping towards a common point or plane. Greek, Syn, with; klino, to bend.

Vitreous, glassy, or like glass. Latin, vitrum, glass.

Volatile, evaporating quickly apt to change. Latin, votare, to fly.