parkinsonite
A tetragonal-ditetragonal dipyramidal mineral containing chlorine, lead, molybdenum, and oxygen.

parnauite
An orthorhombic-disphenoidal mineral containing arsenic, copper, hydrogen, oxygen, and sulfur.

parsettensite
A monoclinic-prismatic copper red mineral containing aluminum, calcium, hydrogen, magnesium, manganese, oxygen, potassium, silicon, and sodium.

parsonsite
A triclinic-pinacoidal mineral containing hydrogen, lead, oxygen, phosphorus, and uranium.

partheite
A monoclinic-prismatic mineral containing aluminum, calcium, hydrogen, oxygen, and silicon.

partzite
An isometric-hexoctahedral mineral containing antimony, copper, hydrogen, and oxygen.

parvowinchite
A monoclinic-prismatic straw yellow mineral containing hydrogen, magnesium, manganese, oxygen, and silicon.

parwelite
A monoclinic-domatic yellow brown mineral containing antimony, arsenic, calcium, magnesium, manganese, oxygen, and silicon.

pascoite
A monoclinic-prismatic mineral containing calcium, hydrogen, oxygen, and vanadium.

paulkellerite
A monoclinic-prismatic greenish yellow mineral containing bismuth, hydrogen, iron, oxygen, and phosphorus.

paulkerrite
An orthorhombic-dipyramidal mineral containing aluminum, fluorine, hydrogen, iron, magnesium, manganese, oxygen, phosphorus, potassium, and titanium.

paulmooreite
A monoclinic-sphenoidal mineral containing arsenic, lead, and oxygen.

pautovite
An orthorhombic-dipyramidal dark steel gray mineral containing cesium, iron, potassium, rubidium, sulfur, and thallium.

pavonite
A monoclinic-prismatic white mineral containing bismuth, copper, lead, silver, and sulfur.

paxite
A monoclinic-prismatic light grayish white mineral containing arsenic and copper.

peagrit
A coarse pisolitic limestone.

peagrits
plural of peagrit

pearceite
A trigonal-hexagonal scalenohedral black mineral containing antimony, arsenic, copper, silver, and sulfur.

pearlite
A two-phased lamellar structure composed of alternating layers of alpha ferrite and cementite that occurs in some steels and cast irons, having a pearlescent appearance.
Alternative form of perlite.

pearlites
plural of pearlite

pearlstone
perlite

pearlstones
plural of pearlstone

peastone
pisolite
pea gravel

peastones
plural of peastone

pecoraite
A monoclinic-prismatic dark green mineral containing hydrogen, nickel, oxygen, and silicon.

pedia
plural of pedion

pedion
An asymmetric triclinic crystal form that only has one face.

pedions
plural of pedion

pedolith
A surface formation that has undergone one or more pedogenic processes; soil.

pegasse
Peat; dark, spongy, acidic, soil of decomposed vegetation (peat), especially in Guyana.

pegmatite
A coarsely crystalline igneous or plutonic rock composed primarily of feldspar and quartz, normally with muscovite and/or biotite mica.

pegmatites
plural of pegmatite

pegmatoids
plural of pegmatoid

peisleyite
A monoclinic white mineral containing aluminum, hydrogen, oxygen, phosphorus, sodium, and sulfur.

pekoite
An orthorhombic-pyramidal lead gray mineral containing bismuth, copper, lead, selenium, and sulfur.

pekovite
An orthorhombic-dipyramidal colorless mineral containing boron, oxygen, silicon, and strontium.

pelite
A sedimentary rock containing very fine particles.

pelites
plural of pelite

pellouxite
A monoclinic-prismatic black mineral containing antimony, chlorine, copper, lead, oxygen, silver, and sulfur.

pellyite
An orthorhombic-dipyramidal mineral containing barium, calcium, iron, magnesium, oxygen, and silicon.

pencatite
A variety of predazzite.

pendletonite
Name for a coronene mineral, later called carpathite.

penfieldite
A hexagonal-dihexagonal dipyramidal mineral containing chlorine, hydrogen, lead, and oxygen.

penikisite
A triclinic-pinacoidal mineral containing aluminum, barium, hydrogen, iron, magnesium, oxygen, and phosphorus.

penkvilksite
A monoclinic-prismatic mineral containing hydrogen, oxygen, silicon, sodium, titanium, and zirconium.

pennantite
A monoclinic-prismatic mineral containing aluminum, hydrogen, manganese, oxygen, and silicon.

pennines
plural of pennine

penobsquisite
A monoclinic-sphenoidal pale yellow mineral containing boron, calcium, chlorine, hydrogen, iron, and oxygen.

penroseite
An isometric-diploidal creamy grayish white mineral containing cobalt, copper, nickel, and selenium.

pentahydroborite
A basic calcium borate found in skarn minerals

pentahydrocalcite
A pentahydrated form of calcite

penzhinite
A hexagonal-trapezohedral grayish white mineral containing copper, gold, selenium, silver, and sulfur.

peperin
A volcanic tufa found in the Alban Hills near Rome.

peretaite
A monoclinic-prismatic mineral containing antimony, calcium, hydrogen, oxygen, and sulfur.

perhamite
A hexagonal-dihexagonal dipyramidal mineral containing aluminum, calcium, hydrogen, oxygen, phosphorus, and silicon.

periclasite
periclase

periclasites
plural of periclasite

pericline
A form of albite exhibiting elongated prismatic crystals.
A periclinal wall.

periclines
plural of pericline

perimorph
A mineral enclosed within another.
The outer mineral that encloses an endomorph.

perimorphs
plural of perimorph

peristerite
A variety of albite, whitish and slightly iridescent.

peristerites
plural of peristerite

perlialite
A hexagonal-dihexagonal dipyramidal pearl white mineral containing aluminum, hydrogen, oxygen, potassium, silicon, and thallium.

perlite
An amorphous volcanic glass formed by the hydration of obsidian.
The lightweight insulating material and aggregate resulting from expanding perlite glass by heat.

perlites
plural of perlite

perloffite
A monoclinic-prismatic mineral containing barium, calcium, hydrogen, iron, magnesium, manganese, oxygen, and phosphorus.

permingeatite
A tetragonal-scalenohedral pink brown mineral containing antimony, copper, and selenium.

perofskite
Alternative form of perovskite.

perofskites
plural of perofskite

perovskite
A minor accessory mineral, CaTiO₃, occurring in basic rocks, as orthorhombic crystals.

perovskites
plural of perovskite

perox
An oxisol in a continuously humid climate, where precipitation exceeds evapotranspiration in all months.

perraultite
A monoclinic-sphenoidal orange brown mineral containing barium, calcium, fluorine, hydrogen, iron, manganese, niobium, oxygen, potassium, silicon, sodium, and titanium.

perroudite
An orthorhombic-disphenoidal light red mineral containing bromine, chlorine, iodine, mercury, silver, and sulfur.

perryite
A trigonal-ditrigonal pyramidal gray white mineral containing iron, nickel, phosphorus, and silicon.

pertsevite
An orthorhombic-pyramidal colorless mineral containing boron, calcium, fluorine, hydrogen, iron, magnesium, manganese, oxygen, and silicon.

petarasite
A monoclinic-prismatic mineral containing calcium, chlorine, hydrogen, oxygen, silicon, sodium, and zirconium.

petedunnite
A monoclinic-prismatic dark green mineral containing calcium, iron, magnesium, manganese, oxygen, silicon, sodium, and zinc.

peterbaylissite
An orthorhombic-dipyramidal mineral containing carbon, hydrogen, mercury, and oxygen.

petewilliamsite
A monoclinic-sphenoidal mineral containing arsenic, calcium, cobalt, copper, iron, nickel, and oxygen.

petitjeanite
A triclinic-pedial mineral containing bismuth, hydrogen, oxygen, and phosphorus.

petrovicite
An orthorhombic-dipyramidal gray mineral containing bismuth, copper, lead, mercury, and selenium.

petrovskaite
A monoclinic mineral containing gold, selenium, silver, and sulfur.

petrukite
An orthorhombic-pyramidal mineral containing copper, indium, iron, silver, sulfur, tin, and zinc.

petscheckite
A trigonal-hexagonal scalenohedral black mineral containing iron, niobium, oxygen, tantalum, and uranium.

petterdite
An orthorhombic-dipyramidal mineral containing aluminum, carbon, chromium, hydrogen, lead, oxygen, and strontium.