Similar to lamellar but with smaller crystals. Nodular A stone of concentric growth around a center usually composed of mostly one mineral. Concretions fall under this term. If broken, may show concentric rings. Oolitic Rounded pebble to sand sized nodules in a compact mass formed in sedimentary environs.
Nodules are larger than oolitic forms.
Radiating Distinct crystals arranged in an orientation outward from a common point. Rosette Petal-like crystals arranged in a flattened radial habit around a central point. Stalactitic A concretionary growth sometimes around a hollow tube, producing long, slowly tappering, rounded masses. Cross-sections usually have circular rings like the rings of a tree. Usually formed in caves or other voids in rocks from the precipitation of a mineral from an evaporating fluid.