Gemmology - Crystal Habits

Slender, needle-like

Poorly formed, has no external faces;Opposite of Euhedral

Layered on the inside, looks like bacon

Hexagonal Pyramid, 2 Pyramids joined at base.

Globular, hemispherical masses, looks like grapes.

Cross-shaped, may be a result of crystalline structure or twinning.

Is a cube, or contains external cubes

Many slender prisms

Tree-like or coral-like

12 sides, each face has 4 edges.

Many tiny crystals (Aggregate) coating a surface

Roughly equal in all directions (Can be a cube, dodecahedron, etc.)

Reflections can be seen from inside the stone, habits and optical characteristics mirrored, left-handed or right-handed form

Well-formed with recognizable faces; Opposite of Anhedral

Hair-like, fine formations

Layered structure that parts into thin sheets

An opaque mother rock (Matrix) with many poorly formed crystals (aggregate) on it.

Has only half the full number of faces in its symmetry classification

Differing forms at opposite ends of its axis of symmetry

Very thin layers, lines all go in 1 direction

Rounded intersecting contours, can also be botryoidal

Shapeless, no individual grains or crystals visible; A chunk

Has 8 sides equal; Octohedron-shaped

Main faces are parallel to C-Axis (Tall)

Only resembles hexagonal due to cyclic twinning;NOT actually hexagonal

Radiating outward from a central point

Crystals forming a net-like intergrowth

6 sides, no 90° angles, tilted.

Platy, radiating, rose-like

Wedge-shaped

6-sided pyramid with unequal sides

Growth lines on the surface of a crystal, parallel (Vertical) or perpendicular (Horizontal) to C-Axis

Short and stubby