Nodule vs. Geode — What's the Difference?

A small knotlike protuberance.

A geode (; from Ancient Greek γεώδης (geṓdēs) 'earthlike') is a geological secondary formation within sedimentary and volcanic rocks. Geodes are hollow, vaguely spherical rocks, in which masses of mineral matter (which may include crystals) are secluded.

(Medicine) A small, abnormal but usually benign mass of tissue, as on the thyroid gland, in the lung, or under the skin.

A hollow, usually spheroidal rock with crystals lining the inside wall.

(Botany) A small knoblike outgrowth, especially one on the roots of a leguminous plant that contains bacteria that fix nitrogen.

(geology) A nodule of stone having a cavity lined with mineral or crystal matter on the inside wall.

(Mineralogy) A small rounded lump of a mineral or mixture of minerals, usually harder than the surrounding rock or sediment.

A nodule of stone, containing a cavity, lined with crystals or mineral matter.

A rounded mass or irregular shape; a little knot or lump.

(mineralogy) a hollow rock or nodule with the cavity usually lined with crystals

A rounded mass or irregular shape; a little knot or lump.

A small node

Small rounded wartlike protuberance on a plant

(mineralogy) a small rounded lump of mineral substance (usually harder than the surrounding rock or sediment)