Mineral Habits Flashcards
Acicular
Needle-shaped; slender and pointed; a crystal habit of some minerals.
Bladed
Flat, elongated, “blade-like” crystals; a type of crystal habit. It describes flattened crystals shaped like a knife blade
Botryoidal
It is a crystal habit describing grape-like warts grown on an otherwise smooth surface.
Cubic
Crystals resembling cubes.
Dendritic
crystals that are unusually large and develop a multi-branching form.
Dodecahedral
minerals that crystallize in the form of dodecahedrons.
Doubly Terminated
This term designates a crystal whose two ends have a termination, that is to say expressed crystal faces.
Druzy
set of tiny crystals of minerals that form on the surface of another stone. Each type of has particular characteristics, such as crystal size, luster and color
Geodic
habit in which mineral aggregates form a rounded or oblate mass by crystallization on the inside walls of a cavity.
Hopper
Crystal form exhibiting an indenting, terraced, structure penetrating towards the center. occurs when electrical attraction is higher along the edges of the crystal; this causes faster growth at the edges than near the face of the crystal.
Massive
Term used to describe a mineral that has no definable shape or form, as its crystals or aggregates are not visible to the unaided eye.
Micaceous/Lamellar
Aggregate of compact, flat, parallel, flexible, and peelable sheets, or describing minerals that occur in such aggregates
Octahedral
Eight sided polyhedron; all sides are equidimensional and bisect at the same angle.
Pisolitic
minerals occur in crystalline aggregates that are rounded and about the size of peas. Individuals are made up of many tiny radiating spheres and occur on mineral surfaces, like deflated botryoidal texture.
Prismatic
Crystal habit describing a crystal with four or more sides similar in length and width.
Radiating/Divergent
A mineral with crystals or fibers arranged around a center point, for example, stibnite. Also called divergent.
Rosette
habit tends to occur when the crystals form in arid sandy conditions, such as the evaporation of a shallow salt basin. Basically resembling a rose.
Stalitic
A crystal habit that resembles stalactites.
Tabular
The structure of a mineral or rock that makes it tend to separate into plates or laminae.
Filiform/Capillary
Like hair or thread
Reticulated
Interconnected like a lattice
Columnar
Stout parallel clusters like a column
Stellate
Long thin crystals radiating in all directions, like a starburst
Spherical/Globular
Compact clusters in rounded, ball-like shapes
Mammilary
Large rounded masses resembling human breasts
Reniform
Radiating compact clusters of crystals ending in rounded, kidney-like, surfaces
Plumose
Feather-like sprays of fine scales, similar to dendritic but with a much finer structure
Banded
Showing different bands or layers of color or texture
