Stalactitic – Forming as stalactites or stalagmites; cylindrical or cone-shaped. Their cross-sections often reveal a “concentric” pattern
2023-03-13
Common examples include: calcite, chrysocolla, goethite, malachiteContinue Reading
Rosette/Lenticular – Platy, radiating rose-like aggregate (also lens shaped crystals)
2023-03-13
Common examples include: gypsum, baryte, calciteContinue Reading
Reticulated – Crystals forming net-like intergrowths
2023-03-13
Common examples include: cerussiteContinue Reading
Radial/Radiating/Divergent – Radiating outward from a central point without producing a star (crystals are generally separated and have different lengths)
2023-03-13
Common examples include: atacamite, stibniteContinue Reading
Plumose – Fine, feather-like scales
2023-03-13
Common examples: aurichalcite, boulangerite, mottramiteContinue Reading
Platy – Flat, tablet-shaped, prominent pinnacoid
2023-03-13
Common examples include: wulfeniteContinue Reading
Pisolitic – Rounded concentric nodules often found in sedimentary rocks. Much larger than oolithic
2023-03-13
Common examples include: bauxite, gibbsiteContinue Reading
Oolithic – Small circumferences or grains (commonly flattened) that resemble eggs
2023-03-13
Common examples include: aragonite, calciteContinue Reading
Hopper – Like cubic, but outer portions of cubes grow faster than inner portions creating a concavity
2023-03-13
Common examples include: halite, calcite, synthetic bismuth A hopper crystal is a form of crystal, the shape of which resembles that of a pyramidal hopper container. The edges of hopper crystals are fully developed, but the interior spaces are not filled in. This results in what appears to be a hollowed out step lattice formation, as if someone hadContinue Reading
Granular – Aggregates of diminute anhedral crystals in matrix or other surface
2023-03-13
Common examples include: andradite, bornite, scheelite, quartzContinue Reading
Foliated/Micaceous/Lamellar – Layered crystal structures, parting into thin sheets
2023-03-13
Common examples include: muscovite, biotite, lepidolite, molybdeniteContinue Reading
Filiform or capillary – Hair-like or thread-like, extremely fine
2023-03-13
Common examples include: many zeolites, byssolite, millerite, okeniteContinue Reading
