mineral

Dendritic Agate (Tumbled)

Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions

Hardness: 6.5-7 (Mohs). Color: White, gray, or translucent with black/brown branch-like inclusions. Luster: Vitreous to waxy. Crystal Structure: Trigonal (Microcrystalline). Cleavage: None. Specific Gravity: 2.60-2.65.

Hardness: 6
Luster: Vitreous to waxy

Identified April 1, 2026More mineral →

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Physical properties

Formation & geological history

Formed when manganese or iron oxides flow through microscopic cracks in chalcedony, precipitating into tree-like patterns known as dendrites. These often occur in volcanic rocks or hydrothermal veins.

Uses & applications

Primarily used in jewelry (cabochons), lapidary art, collection specimens, and metaphysical practices (stone of plenitude).

Geological facts

The 'dendrites' are not fossils but rather mineral stains that mimic botanical growth. Carl Fabergé, the jeweler to the Russian Tsar, famously used dendritic agate in his artwork.

Field identification & locations

Identify in the field by its characteristic 'fern-like' or 'moss-like' patterns inside translucent to opaque white/gray chalcedony. It won't scratch with a copper penny or steel knife.

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