tufa, stalagmite, metamorphic rock, moulins, cumulus cloud, tympanum, tumulus, dolmen, calcite, igneous rock, ferny, whorled, sandstone, hummocks, azurite, crenellations, ashlar, syrtis major, concretions, fingerlike, outwash, limestone, oculus, caryatids, hoarfrost, crinoid, massifs, conodonts, umbels, stromatolite, goethite, tetrahedron, volcanic crater, ovoid, duckbill, pentagonal, lobate, verdigris, flowerlike, stratovolcano, opaline, spadix, claystone, pilaster, coprolite, henge, chalcedony, hogback, basaltic, cragged, whorls, stippled, cenote, omega centauri, cavelike, anhydrite, tracery, toroid, icosahedral, lunette, cavern, potsherds, spathe, asthenosphere, plagioclase, hornblende, geode, grottos, semicircles, halite, striations, eskers, mantling, isosceles triangle, metopes, ammonite, ogee, strangler fig, glasslike, dolerite, pediments, yellow ocher, conical, acanthus, rock outcrop, lacework, lapilli, argillaceous, travertine, apse, tesserae, rills, slickrock, pegmatitic, siderite, cumulonimbus cloud, cinnabar, scoria, glacial boulder, coralline, polychrome, graben, stalactites, amethyst, sapphire, stalagmites, candelabra, emerald, opal, arrowhead, bubble, canopy, chandelier, chimney, icicles, kite, obelisk, obelisks, ruby, spar, thimble, corbelled, foliate, stalactitic, foliated, frescoed, moulded, fretted, ogival, domical, ribbed, romanesque, stuccoed, vaulted, cusped, gothic, rosette, sculptured, zoomorphic, apsidal, arched

cave

cylinder