"Peperino" is a word in ENGLISH

A mass of angular volcanic fragments united by heat; -- distinguished from conglomerate.

Minute acicular or dendritic crystalline forms sometimes observed in glassy volcanic rocks.

bolkán - (Sp. volcan) Volcano.

A mineral, composed of silica, magnesia, and iron, of a yellow to green color. It is common in certain volcanic …

Anything shaped more or less like a mathematical cone; as, a volcanic cone, a collection of scoriae around the crater …

A minute mineral form like those common in glassy volcanic rocks and some slags, not having a definite crystalline outline …

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

Pertaining to Etna, a volcanic mountain in Sicily.

A variety of opal occuring in the cavities of volcanic tufa, in smooth and shining globular and botryoidal masses, having …

A hole or spot in a volcanic or other region, from which fumes issue.

A low, oven-shaped mound, common in volcanic regions, and emitting smoke and vapors from its sides and summit.

Situated between hills; -- applied especially to valleys lying between volcanic cones.

Volcanic ashes, consisting of small, angular, stony fragments or particles.

A mineral having a glassy fracture, occurring in translucent trapezohedral crystals. It is a silicate of alumina and potash. It …

A spherulitic cavity often with concentric chambers, observed in some volcanic rocks, as in rhyolitic lavas. It is supposed to …

Native sulphate of ammonia, found in volcanic districts; -- so named from Mascagni, who discovered it.

A glassy volcanic rock of a grayish color and pearly luster, often having a spherulitic concretionary structure due to the …

Volcanic ashes from Pozzuoli, in Italy, used in the manufacture of a kind of mortar which hardens under water.

A very light porous volcanic scoria, usually of a gray color, the pores of which are capillary and parallel, giving …

Cellular slaggy lava; volcanic cinders.