Definition of spherulite

i. A rounded or spherical mass of acicular crystals, commonly of feldspar, radiating from a central point. Spherulites may range in size from microscopic to several centimeters in diameter. Also spelled: sphaerolite.


Ref: AGI

ii. Any more or less spherical body or coarsely crystalline aggregate with a radial internal structure arranged around one or more centers, varying in size from microscopic grains to objects many centimeters in diameter, formed in a sedimentary rock in the place where it is now found; e.g., a minute particle of chalcedony in certain limestones, or a large carbonate concretion or nodule in shale.

Compare with: spherite, variole

Ref: AGI

iii. A small (0.5 to 5 mm in diameter), spherical or spheroidal particle composed of a thin, dense calcareous outer layer with a sparry calcite core. It can originate by recrystallization or by biologic processes.

Ref: AGI