sedimentary

Nile Agate

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 Mohs. Color: translucent brown, honey, and greyish-green with visible concentric banding. Luster: waxy to vitreous. Structure: Cryptocrystalline quartz. Cleavage: None (conchoidal fracture).

Hardness: 6
Luster: waxy to vitreous

Identified July 18, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed by the deposition of silica from groundwater within cavities (vesicles) of igneous rocks or sedimentary voids. These specimens are often weathered out and transported by fluvial processes, common in the Cenozoic sediments of the Nile Basin.

Uses & applications

Used primarily for jewelry (cabochons, beads), decorative lapidary work, and as a collectible gemstone.

Geological facts

Nile agates are known for their beautiful, intricate banding and are often found as water-worn pebbles in the deserts of Sudan and Egypt. They have been used for thousands of years in the making of amulets and beads in ancient Saharan cultures.

Field identification & locations

Identify by looking for waxy luster, translucency when held to light, and characteristic 'eye' or linear banding. Highly consistent with the geology of North-Eastern Sudan (17.6°N, 34.0°E), which features vast Cretaceous to Tertiary sedimentary deposits and gravel plains containing silica-rich nodules.