mineral

Agate

SiO2 (Silicon Dioxide) - Chalcedony

AI-generated identification · may be incorrect

Hardness: 6.5-7, Color: variable, typically banded (this piece shows orange/brown with translucent areas), Luster: Waxy to vitreous, Crystal structure: Cryptocrystalline, Cleavage: None, Specific gravity: 2.58-2.64

Hardness: 6

Identified August 25, 2026More mineral →

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Physical properties

Formation & geological history

Forms in cavities of eruptive rocks or ancient lavas from silica-rich fluids over millions of years.

Uses & applications

Used in jewelry, lapidary arts, ornaments, and by rock hounds for tumbling and collecting.

Geological facts

Agate was named by Theophrastus, a Greek philosopher and naturalist, who discovered the stone along the shore line of the Achates River in Sicily.

Field identification & locations

Identify by its waxy luster, translucency, and often banded appearance. Commonly found worldwide, often in volcanic areas, riverbeds, and beaches.

Other mineral specimens

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Gneiss or Schist

Gneiss or Mica Schist with Garnet

Metamorphic

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Calcite–fluorite mineral specimen with iron-oxide staining

Calcite (CaCO₃), likely fluorite (CaF₂), with possible quartz and iron/manganese oxides

mineral

Mineral Sand (Heavy Mineral Sand Concentrate)

Placer deposit concentrate containing minerals such as ilmenite, rutile, zircon, and magnetite

mineral

Septarian Pebble

Septarian nodule / Concretion

sedimentary

Granite

Granite (Phaneritic intrusive igneous rock)

igneous