one axis and arranged in linear parallel structure.perliteperlitType of volcanic glass. It seems to be composed of many small particles "pearls".permeabilitypermeabilitaThe capacity of a rock to transmit a fluids (liquids or gases).PermianpermThe youngest period of Paleozoic (from 245 to 286 mil. of years ago).phaneriticfaneritickyA textural term applied to igneous rocks in which all the crystals of the essential minerals can be distinguished with the unaided eye. The adjective form phaneritic is currently used more frequently than the noun.phenocrystporfyricka vyrostliceAny of the large crystals in porphyritic igneous rock.phonoliteznilec (fonolit)Type of rock composed of feldspars, foids, pyroxenes and amphiboles.phthanitebuli?nikBiochemical sedimentary rock, mostly black in colour, composed of silica.phyllitefylitA metamorphic rock in which clay minerals have recrystallized into microscopic micas, giving the rock a silky sheen.pitch lustersmolny leskA luster that gives a substance pitch appearance.pitchstonesmolekType of volcanic glass with typical pitch luster.plagioclasessodnovapenate ?ivceSubgroup of feldspars containing sodium and/or calcium in addition to aluminium, silicon, and oxygen. Properties see feldspars.plate tectonicsdeskova tektonikaA theory that the earth's surface is divided into a few large, thick plates that are slowly moving and changing in size. Intense geologic activity occurs at the plate boundaries.plateaunahorni rovinaBroad, flat-topped area elevated above the surrounding land and bounded, at least in part, by cliffs.plunging foldvrasaA fold in which the hinge line (or axis) is not horizontal.plutonplutonAn igneous body that crystallized deep underground.plutonic rockshlubinne horninyIgneous rocks formed at great depth.polar wanderingmigrace poluAn apparent movement of the earth's poles.polymictpolymiktni(valouny vice druhu)Within psefitic sediments or sedimentary rocks, term describing composition of many types of fragments.porcelaniteporcelanitMetamorphic rock with typical conchoidal fracture and sharp edges which was formed by contact metamorphism of pelitic sediments.pore spaceintergranularni prostorThe total amount of space taken up by openings between sediment grains.porosityporositaThe percentage of a rock's volume that is taken up by openings.porous structureporovita texturaStructure of a rock where part of rock volume is taken up by openings.porphyritic textureporfyricka strukturaTexture of those igneous rocks in which larger crystals (phenocrysts) are set in a finer groundmass which may be crystalline or glassy, or both.porphyroblastic textureporfyroblasticka strukturaTexture of metamorphic rocks very similar to porphyritic texture of igneous rocks (groundmass cannot be glassy).potassium feldspardraselny ?ivecA feldspar with the formula KAlSi3O8.Precambrian timeprekambriumThe vast amount of time that preceded the Paleozoic Era (before 570 mil. of years).psammitespsamityClastic sediments or sedimentary rocks with sizes of particles between 0.06 and 2 mm.psefitespsefityClastic sediments or sedimentary rocks with size of particles over 2 mm.pyritepyritMineral with formula FeS2 with "gold" appearance. It is sometimes present as accessory mineral in igneous rocks.pyroclastic rockspyroklastikaRocks formed by lithification of pyroclasts.pyroclastspyroklastikaFragments of rocks formed by volcanic explosion.pyroxenepyroxenFerromagnesian mafic mineral which belongs to silicates. Black to dark-green in colour, vitreous to dull luster. Hardness is from 5 to 6. It has two imperfect cleavages meet at nearly 90 degrees (it is not often macroscopically visible). Shape is usually short columnar.quarrylomAn open or surface working, usually for the extraction of building stone, as slate, limestone, etc. In its widest sense the term mines includes quarries, and has been sometimes so construed by the courts; but when the distinction is drawn, mine denotes underground workings and quarry denotes superficial