mineralhabit

Mineral habit refers to the characteristic external shape or aggregate form that a mineral crystal or group of crystals takes when it grows in an open space. It is a macroscopic property and is independent of the mineral's internal atomic structure, although the crystal structure influences the habit. Habit is often described using specific terms to categorize the various forms observed.

Common mineral habits include massive, where the mineral occurs as a shapeless aggregate; granular, composed of numerous small, interlocking grains; columnar, elongated in one direction into prisms or needles; bladed, flattened and elongated like a knife blade; fibrous, made up of fine, thread-like crystals; botryoidal, resembling a bunch of grapes; reniform, kidney-shaped; dendritic, branching like tree branches; and cubic, forming distinct cube shapes.

The habit of a mineral can be influenced by various factors during its formation, such as the rate of crystallization, the presence of impurities, the physical and chemical conditions of the environment (temperature, pressure, solvent), and the presence of other minerals. While a mineral's crystal system dictates the possible angles between its faces and the fundamental geometry of its unit cell, the habit describes how these internal structures manifest externally. Understanding mineral habit is an important tool for mineral identification, alongside properties like color, luster, and hardness.