Category: Rounded/Spherical habits
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Reniform – Kidney-shaped masses
Common examples include: cassiterite, chalcedony, chrysocolla, hematite, fluorite, goethite, greenockite, malachite, wavellite, mottramite
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Mammillary – Breast-like: surface formed by intersecting partial spherical shapes, larger version of botryoidal and/or reniform, also concentric layered aggregates. It is almost synonymous with reniform.
Common examples include: chalcedony, hematite, malachite
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Botryoidal – Grape-like, large and small hemispherical masses, nearly differentiated/separated from each other
Common examples include: chalcedony, pyrite, smithsonite, hemimorphite A botryoidal (/ˌbɒtriˈɔɪdəl/ BOT-ree-OY-dəl) texture or mineral habit, is one in which the mineral has an external form composed of many rounded segments, named for the Ancient Greek βότρυς (bótrus), meaning “a bunch of grapes“. This is a common form for many minerals, particularly hematite and malachite, which are known for frequently forming botryoidal masses. It is also a common form of goethite, smithsonite, fluorite, and chrysocolla.…
