mineral

Blue Agate (Dyed)

Silicon Dioxide (SiO2) - Variety of Chalcedony

Hardness: 6.5–7 (Mohs scale); Color: Artificial blue with white/clear bands; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific gravity: 2.60–2.65.

Hardness: 6
Color: Artificial blue with white/clear bands
Luster: Vitreous to waxy

Identified March 18, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 6.5–7 (Mohs scale); Color: Artificial blue with white/clear bands; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific gravity: 2.60–2.65.

Formation & geological history

Formed in cavities (vesicles) of volcanic rocks or ancient hydrothermal veins. Typically millions of years old; the silica layers precipitate over time from groundwater. Note: The intense blue color is achieved via artificial dyeing of porous Brazilian or Uruguayan agate.

Uses & applications

Used primarily for ornamental purposes, home decor, wind chimes, bookends, and low-cost jewelry (beads and pendants).

Geological facts

Agates are porous, which allowed the ancient Romans to develop dyeing techniques to enhance their appearance. Many bright blue, pink, or purple agates in the market today are natural grey agates that have been chemically treated.

Field identification & locations

Identify by characteristic concentric banding. In the field, look for 'nodules' with a rough, warty exterior but a waxy, glassy interior when broken. Natural blue agate (like Blue Lace) is much paler and lacks the intense, uniform saturation seen in this specimen.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral