Studied by 36 PeopleAcicular
Tags & Description
Acicular
Slender, needle-like
Anhedral
Poorly formed, has no external faces;Opposite of Euhedral
Banded
Layered on the inside, looks like bacon
Bipyramidal
Hexagonal Pyramid, 2 Pyramids joined at base.
Botryoidal
Globular, hemispherical masses, looks like grapes.
Cruciform
Cross-shaped, may be a result of crystalline structure or twinning.
cube
Is a cube, or contains external cubes
Columnar/Fibrous
Many slender prisms
Dendritic
Tree-like or coral-like
Dodecahedral
12 sides, each face has 4 edges.
Drusy
Many tiny crystals (Aggregate) coating a surface
Equant
Roughly equal in all directions (Can be a cube, dodecahedron, etc.)
Enantimorphic
Reflections can be seen from inside the stone, habits and optical characteristics mirrored, left-handed or right-handed form
Euhedral
Well-formed with recognizable faces; Opposite of Anhedral
Filiform Capillary
Hair-like, fine formations
Foliated Micaceous
Layered structure that parts into thin sheets
Granular
An opaque mother rock (Matrix) with many poorly formed crystals (aggregate) on it.
Hemihedral
Has only half the full number of faces in its symmetry classification
Hemimorphic
Differing forms at opposite ends of its axis of symmetry
Lamellar
Very thin layers, lines all go in 1 direction
Mamillary
Rounded intersecting contours, can also be botryoidal
Massive
Shapeless, no individual grains or crystals visible; A chunk
Octohedral
Has 8 sides equal; Octohedron-shaped
Prismatic
Main faces are parallel to C-Axis (Tall)
Pseudo-Hexagonal
Only resembles hexagonal due to cyclic twinning;NOT actually hexagonal
Radiating Divergent
Radiating outward from a central point
Reticulated
Crystals forming a net-like intergrowth
Rhombohedron
6 sides, no 90° angles, tilted.
Rosette
Platy, radiating, rose-like
Sphenoid
Wedge-shaped
Scalenohedron
6-sided pyramid with unequal sides
Striation
Growth lines on the surface of a crystal, parallel (Vertical) or perpendicular (Horizontal) to C-Axis
Tabular
Short and stubby
