coprolite
A fossil consisting of petrified dung.

coquandite
A triclinic-pinacoidal mineral containing antimony, hydrogen, oxygen, and sulfur.

corallian
A deposit of coralliferous limestone forming a portion of the middle division of the oolite.

corallians
plural of corallian

corderoite
An isometric-tetartoidal mineral containing chlorine, mercury, and sulfur.

corkite
A trigonal-ditrigonal pyramidal mineral containing hydrogen, iron, lead, oxygen, phosphorus, and sulfur.

cornbrash
A coarse calcareous sandstone in various parts of England

cornbrashes
plural of cornbrash

cornetite
A mineral containing copper, hydrogen, oxygen, and phosphorus.

cornstone
A kind of marly siliceous rock.

cornstones
plural of cornstone

cornubianite
A dark-blue laminated rock found in Cornwall with granite.

cornubianites
plural of cornubianite

coronadite
A monoclinic-prismatic mineral containing aluminum, barium, lead, manganese, oxygen, and vanadium.

coronite
Tiny grains of titanium nitride evenly dispersed in a heat treatable steel matrix, resulting in a manufactured material that combines the toughness of steel with the wear resistance of carbide.

corpohuminite
A maceral of the huminite group.

corrensite
An orthorhombic mineral containing aluminum, calcium, hydrogen, iron, magnesium, oxygen, potassium, silicon, and sodium.

corsite
Synonym of napoleonite.

corsites
plural of corsite

cortlandtite
A variety of peridotite composed of large crystals of hornblende.

cortlandtites
plural of cortlandtite.

corundophilite
An iron-rich variety of clinochlore.

corvusite
A monoclinic-prismatic mineral containing calcium, hydrogen, oxygen, potassium, sodium, and vanadium.

cosalite
An orthorhombic-dipyramidal mineral containing bismuth, lead, and sulfur.

cosalites
plural of cosalite

cossyrite
Synonym of aenigmatite.

cossyrites
plural of cossyrite

costibite
An orthorhombic-pyramidal steel gray mineral containing antimony, cobalt, and sulfur.

coticule
A Belgian variety of whetstone, containing spessartine.

coulsonite
An isometric-hexoctahedral blue gray mineral containing iron, oxygen, and vanadium.

courtzilite
A type of asphalt allied to uintahite and gilsonite.

coutinhoite
An orthorhombic-dipyramidal yellow mineral containing barium, calcium, hydrogen, oxygen, phosphorus, potassium, silicon, thorium, and uranium.

couzeranite
A scapolite mineral.

covelline
covellite

covellines
plural of covelline

cowlesite
An orthorhombic mineral containing aluminum, calcium, hydrogen, oxygen, and silicon.

coyoteite
A triclinic black mineral containing hydrogen, iron, oxygen, sodium, and sulfur.

craigmontite
A nephelite-oligoclase-muscovite rock.

crandallite
A trigonal-hexagonal scalenohedral mineral containing aluminum, calcium, hydrogen, oxygen, and phosphorus.

crawfordite
A monoclinic-sphenoidal mineral containing carbon, oxygen, phosphorus, sodium, and strontium.

creaseyite
An orthorhombic-dipyramidal mineral containing aluminum, copper, hydrogen, iron, lead, oxygen, and silicon.

creedite
A monoclinic-prismatic mineral containing aluminum, calcium, fluorine, hydrogen, oxygen, and sulfur.

crerarite
An isometric-hexoctahedral black mineral containing bismuth, lead, platinum, selenium, and sulfur.

crestmoreite
A supposed mineral, later found to be a mixture of ellestadite and tobermorite.

criddleite
A monoclinic-prismatic black mineral containing antimony, gold, silver, sulfur, and thallium.

crocidolite
A fibrous, blue-green mineral that is a variety of riebeckite and is one of the six types of asbestos.

crocidolites
plural of crocidolite

crocoisite
Alternative form of crocoite.

crocoite
A rare red mineral; lead chromate, PbCrO₄.

crocoites
plural of crocoite

cromfordite
Synonym of phosgenite.

cronstedtite
A trigonal-ditrigonal pyramidal mineral containing hydrogen, iron, oxygen, and silicon.

cronusite
A trigonal coal black mineral containing calcium, chromium, hydrogen, oxygen, and sulfur.

crookesite
A tetragonal-disphenoidal mineral containing copper, selenium, silver, and thallium.

crowstone
Ganister, a kind of sandstone.

crowstones
plural of crowstone

cryert
A vertisol with a cryic soil temperature regime.

cryerts
plural of cryert

cryolite
The mineral sodium hexafluoroaluminate (Na₃AlF₆).

cryolites
plural of cryolite

cryolithionite
An isometric-hexoctahedral mineral containing aluminum, fluorine, lithium, and sodium.

cryolithozone
The rocky part of the cryosphere

cryptoclase
Synonym of albite.

cryptoflysch
Any flysch-like material other than sandstone or schist which is found in similar formations.

cryptohalite
An isometric-hexoctahedral mineral containing fluorine, hydrogen, nitrogen, and silicon.

cryptomelane
A monoclinic-prismatic mineral containing manganese, oxygen, and potassium.

crystalware
Items, especially tableware, made from crystal.

crystobalite
Alternative form of cristobalite.

crystobalites
plural of crystobalite

cualstibite
A trigonal-rhombohedral blue green mineral containing aluminum, antimony, copper, hydrogen, and oxygen.

cubanite
An orthorhombic-dipyramidal mineral containing copper, iron, and sulfur.

cuboargyrite
An isometric-hexoctahedral grayish black mineral containing antimony, silver, and sulfur.

culet
A component of armor, consisting of overlapping plates designed to protect the buttocks.
A small, flat face often cut at the base of a brilliant-cut gemstone.

culets
plural of culet

culette
Alternative form of culet (“type of armour”).

culettes
plural of culette

culsageeite
A variety of jefferisite from Culsagee, North Carolina.

cumberlandite
A variety of melatroctolite.

cumberlandites
plural of cumberlandite.

cumengite
A tetragonal-ditetragonal dipyramidal indigo blue mineral containing chlorine, copper, hydrogen, lead, and oxygen.

cupalite
A rare mineral of copper and aluminium, closely related to khatyrkite.

cuproadamite
A copper containing variety of adamite.

cuprocopiapite
A triclinic-pinacoidal mineral containing copper, hydrogen, iron, oxygen, and sulfur.

cuprodescloizite
Synonym of mottramite.

cuproiridsite
An isometric-hexoctahedral gray mineral containing copper, iridium, and sulfur.

cupromakovickyite
A monoclinic-prismatic gray mineral containing bismuth, copper, lead, selenium, silver, sulfur, and tellurium.

cupromolybdite
A fumarolic mineral with formula Cu₃O(MoO₄)₂

cupromontmorillonite
Synonym of medmontite.

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

cuprorhodsite
An isometric-hexoctahedral gray mineral containing copper, rhodium, and sulfur.

cuprorivaite
A tetragonal-ditetragonal dipyramidal blue mineral containing calcium, copper, oxygen, and silicon.

cuproscheelite
A mineral (CuWO₄) having the same structure as scheelite but with calcium replaced by copper.

cuprosklodowskite
A triclinic-pinacoidal mineral containing copper, hydrogen, oxygen, silicon, and uranium.

cuprospinel
An isometric-hexoctahedral black mineral containing aluminum, copper, iron, magnesium, and oxygen.

cuprospinels
plural of cuprospinel

cuprostibite
A tetragonal-ditetragonal dipyramidal steel gray mineral containing antimony, copper, and thallium.

cuprotungstite
A tetragonal mineral containing copper, hydrogen, oxygen, and tungsten.

cuprouranite
The mineral copper uranite or torbernite.

curetonite
A monoclinic-prismatic mineral containing aluminum, barium, hydrogen, oxygen, phosphorus, and titanium.

curf
A limestone containing cherts

curfs
plural of curf

curienite
An orthorhombic-dipyramidal canary yellow mineral containing hydrogen, lead, oxygen, uranium, and vanadium.

curite
An orthorhombic-dipyramidal mineral containing hydrogen, lead, oxygen, and uranium.

curites
plural of curite

curtisite
A variety of idrialite found in the Skaggs Springs region of California.

cuspidine
A monoclinic-prismatic mineral containing calcium, fluorine, hydrogen, oxygen, and silicon.

cuspidines
plural of cuspidine