geode
A nodule of stone having a cavity lined with mineral or crystal matter on the inside wall.
Noun
- A nodule of stone having a cavity lined with mineral or crystal matter on the inside wall.
Origin
From French géode, from Latin geōdēs, from Ancient Greek γεώδης (geṓdēs, “earthlike”), equivalent to γῆ (gê, “earth”) + -ώδης (-ṓdēs).