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Habit: Terms. Acicular, Capillary, Filiform, Bladed, Dendritic, Radiating, Drusy, Fibrous Globular, Colloform, Foliated, Micaceous, Tabular, Lamellar, Plumose Granular, Columnar, Prismatic. Acicular.
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Habit: Terms • Acicular, Capillary, Filiform, Bladed, Dendritic, Radiating, Drusy, Fibrous • Globular, Colloform, Foliated, Micaceous, Tabular, Lamellar, Plumose • Granular, Columnar, Prismatic
Acicular • slender, needle-like crystals:tourmaline, hornblende, arsenopyrite, rutile, apatite, sillimanite
Capillary and filiform • hair-like or thread-like: native Au, Ag, Cu
Bladed • elongated crystals flattened like a knife blade: kyanite, tremolite
Dendritic • arborescent, in slender divergent branches, somewhat plantlike--native metals, pyrolusite
Radiating • divergent: zeolite; tremolite; talc • pyrolusite, tourmaline
Drusy • surface covered with a layer of small crystals--sugar like: calcite, quartz, sphalerite, pyrite
Fibrous • aspect ratio 10:1 • chrysotile asbestos
Globular and colloform • radiating individuals forming small spherical groups • examples include zeolites, quartz, malachite, goethite, pyrolusite, hematite
Botryoidal • bunch of grapes, example pyrolusite
Reniform • kidney like, examples hematite, malachite
Mammillary • -very large, example is malachite
Foliated • easily separable into plates or leaves: tremolite; hematite
Micaceous • similar to foliated but splits into very thin sheets: muscovite, biotite, chlorite
Tabular or lamellar • flat and platelike: barite, dolomite
Granular • composed of many individual grains of similar size: olivine, garnet
Prismatic or columnar • elongated crystals with identical faces parallel to a common direction: tourmaline, hornblende, apatite