mineral

Plume Agate or Moss Agate

Agate (SiO2)

Hardness: 6.5-7 (Mohs scale), Color: Grayish, translucent with white inclusions, Luster: Waxy to vitreous, Crystal structure: Cryptocrystalline, Cleavage: None, Specific gravity: 2.58-2.64

Hardness: 6

Identified June 19, 2026More mineral →

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Physical properties

Hardness: 6.5-7 (Mohs scale), Color: Grayish, translucent with white inclusions, Luster: Waxy to vitreous, Crystal structure: Cryptocrystalline, Cleavage: None, Specific gravity: 2.58-2.64

Formation & geological history

Forms in voids of volcanic or sedimentary rocks via silica deposition from groundwater. The white 'plume' or 'moss' like inclusions are typically minerals like chlorite, manganese, or iron oxides, though in this case they appear to be white chalcedony or other silica-based formations.

Uses & applications

Used primarily in jewelry, cabochons, and for rock collecting.

Geological facts

Agate is a variety of chalcedony. The delicate, fern-like or plume-like patterns are highly prized by collectors.

Field identification & locations

Identify by its waxy luster, hardness (can scratch glass), and distinctive semi-translucent body with opaque patterned inclusions. Commonly found worldwide, especially in volcanic regions like the Americas, India, and Brazil.