- C
-
- Cabochon
- Calcareous
- Calcic
- Calcite group
- Cameo
- Capillary
- Carat
- Carbonates (group)
- Carlsbad twin
- Carved
- Carving
- Cassiterite twin
- Cation
- Cat's eye
- Catseye
- Cat's eye effect
- Cave
- Cavern
- Cavity
- Cementation zone
- Center of symmetry
- Chain silicates
- Chatoyancy
- Chatoyant
- Chemical
- Chemical bond
- Chemical composition
- Chemical formula
- Chemical structure
- Chemistry
- Chemist
- Chromates (group)
- Chrysoberyl twin
- Clast
- Clay
- Cleavable
- Cleavage
- Cleavage angle
- Cleavage fragment
- Cleave
- Cleaved
- Cleaved surface
- Cleaving
- Clinopinicoid
- Clinopinicoidal
- Cluster
- Coal
- Coating
- Cockscomb
- Color
- Columnar
- Composition
- Compound
- Concentric
- Conchoidal (fracture)
- Concretion
- Conductivity
- Conductor
- Contact metamorphism
- Contact twinning
- Coprolite
- Coral
- Core
- Coxcomb
- Crater
- Crazing
- Crumbly
- Crust
- Crust (earth layer)
- Crusty
- Cryptocrystalline
- Crystal
- Crystal aggregate
- Crystal angle
- Crystal class
- Crystal face
- Crystal form
- Crystal group
- Crystal habit
- Crystal lattice
- Crystal structure
- Crystal symmetry
- Crystal system
- Crystalline
- Crystallization
- Crystallize
- Crystallized
- Crystallographically
- Crystallography
- Crystallographer
- Ct.
- Cube
- Cubic (crystal system)
- Cubic (shape)
- Cubic cleavage
- Cubic octahedron
- Cut (noun)
- Cut (verb)
- Cyclosilicates (subgroup)
- Cymophane effect