mineral

Dyed Agate Slice

Silicon Dioxide (SiO2) - variety of Chalcedony

Hardness: 6.5-7 (Mohs scale); Color: Neon blue and vibrant magenta (dyed), naturally grey or white; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.6

Hardness: 6
Luster: Vitreous to waxy

Identified March 14, 2026More mineral →

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Physical properties

Formation & geological history

Formed in cavities of volcanic rocks or ancient lavas. Silica-rich groundwater deposits layers of microcrystalline quartz over thousands of years. These specimens are often sourced from Cenozoic era formations in Brazil.

Uses & applications

Primarily used for decorative purposes, coasters, jewelry cabochons, metaphysical 'healing' crystals, and as educational specimens in geology kits.

Geological facts

Natural agate is rarely this vibrant; the intense blue and pink seen here are the result of an artificial dyeing process. Agate is porous enough to absorb chemical dyes, a practice that dates back to ancient Roman times.

Field identification & locations

Identify in the field by its distinct concentric banding and waxy texture. Slices like these are commonly found in gift shops and mineral shows, often originating from Rio Grande do Sul, Brazil. Look for the rough 'skin' or cortex on the outer edge.

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