Near to the holy town Aksum (a sanctuary of the coptic church) agate nodules do occur in a vulcanic host-rock. This material was first brought from Prof. Petranek, a tschechian geologist, in the early 1990ies to Europe.
These nodules are reaching sizes up to 25cm in diameter but are mostly weak coloured in grey and white. Some specimen may show the agate-variety “Wegeler” - agates with a shadow-effect. ( a shadow is moving between transparent and opaque layers in the fine structured agate-banding). Some nodules are showing a sedimentation towards the bottom that is reminding the “Membrantrümmer-structure”.