euhedral
Fully developed faces
Euhedral describes a crystal that has developed its full, characteristic geometric shape with well-formed faces and sharp edges.
The term appears in geology and mineralogy when crystals grow without interference from neighboring minerals: The rock contained euhedral quartz crystals.
The opposite is anhedral, describing crystals with no defined faces.
Front of heads
- edgesOuter limits or boundaries
- verticesCorner points of shapes
- terminationAct of ending something
- prismLight-splitting optical element
pyramid · rhombohedron · dodecahedron · striation · luster · transparency · sharp · distinct
Structurally correct and complete
- hexagonalSix-edged polygon's form
- cubicOf three dimensions
- trigonalThree-angled in form
- isometricHaving uniform measurements
prismatic · habit · symmetry · lattice · cleavage · twinning · zoning · inclusion
Formed from cooled magma
- magmaMolten rock underground
- volcanicOf fiery mountain origin
- plutonicDeep-crystallized igneous rock
- metamorphicUndergoing structural change
hydrothermal · vein · cavity · geode · matrix · groundmass · nucleation · growth
faces
Front of heads
- edgesOuter limits or boundaries
- verticesCorner points of shapes
- terminationAct of ending something
prism · pyramid · rhombohedron · dodecahedron · striation · luster · transparency · sharp · distinct · bounded
well-formed
Structurally correct and complete
isometric · prismatic · habit · symmetry · lattice · cleavage · twinning · zoning · inclusion · overgrowth
igneous
Formed from cooled magma
metamorphic · hydrothermal · vein · cavity · geode · matrix · groundmass · nucleation · growth · precipitation
quartz
Crystalline silicon dioxide
amphibole · feldspar · biotite · muscovite · magnetite · pyrite · zircon · tourmaline · beryl · apatite
- rock texturescoarse-grained, fine-grained, grainy, gritty, massive