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Mineral HabitsGeology 40I. Individual* Acicular - composed of a radiating mass of slender, needle-like crystals. minerals with this habit tend to be fragile, and complete, undamaged specimens can be uncommon.

Millerite, Natrolite

Bladed - blade-like, slender and flattened, similar to grass.

|Actinolite, Kyanite

Equant - any three perpendicular axis through the crystal are more or less equal. can be used to describe rounded as well as angular crystals.

Fluorite, Galena

Tabular/Stubby/Blocky - book-like (tablets) that are thicker than platy but not as elongated as bladed.

Oligoclase, Baryte

Platy - flat, tablet-shaped, prominent pinacoid.

Wulfenite, Hematite Prismatic/Columnar - elongated, prism-like: crystal faces parallel to c-axis are well-developed. pencil-like

Tourmaline, Calcite

Capillary/Filiform - hair-like or thread-like, extremely fine

Millerite, Pyrite

Striated - not a habit per se, but a condition of lines that can grow on certain crystal faces on certain minerals.

Tourmaline, SpodumeneII. Aggregate Amygdaloidal almond-shaped, bubble-shaped cavities that have become filled with minerals.

Calcite, Epidote

Fibrous - aggregates of parallel or radiating slender fibers. extremely slender prisms.

Rutilated Quartz, Silver

Botryoidal - resembling grape bunches with interlocking rounded masses.

Hematite, Sphalerite Mammillary - rounded, literally "breast-like" masses, similar to botryoidal and globular but more rounded, larger individual masses.

Chalcedony, Malachite

Globular - bubbly, rounded masses, similar to botryoidal or mammillary but less coherent.

Fluorite, Wavellite

Reniform - "kidney form" - each globular structure has an internally radiating form.

Hematite, Malachite Radiating/Divergent - growing outward from a point in sprays or starbursts. distinct crystals arranged in an orientation outward from a common point.

Pyrite Sun, Adamite

Reticulated - crystals forming net-like intergrowths.

Cerussite, Rutile

Roseiform/Rosette/Lenticular - tabular or bladed crystals in a cluster. can also be radiating rose-like aggregate.

Baryte, Gypsum Drusy/Druzy - aggregate of minute crystals coating a surface or cavity (geode).

Azurite, Amethyst

Dendritic/Arborescent - tree-like, branching in one or more direction from central point.

Pyrolusite, Copper

Foliated/Lamellar/Micaceous - layered structure, parting into thin sheets.

Lepidolite, Talc Massive/Compact - no crystal structure visible, though the mineral may be crystalline. some massive minerals may also be granular. shapeless, no distinctive external crystal shape.

Turquoise & Quartz, Forsterite & Magnetite

Granular - aggregates of anhedral crystals in matrix. crystals of a small size, less than 1 cm across, that exhibit no really discernable crystal form.

Bornite, Pyroxene & Omphacite

Banded - parallel layers of same mineral with different colors.

Rhodochrosite, Goethite

Oolitic - rounded pebble to sand sized nodules (