mineral

Agate (Carnelian / Fire Agate nodule)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Hardness: 6.5-7 on Mohs scale; Color: translucent chalcedony matrix with fiery orange, red-brown, and brownish iron oxide inclusions/botryoidal patterns; Luster: waxy to vitreous; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture).

Hardness: 6
Luster: waxy to vitreous

Identified July 24, 2026More mineral →

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Physical properties

Formation & geological history

Formed in cavities of volcanic rocks (basalt/andesite) where silica-rich hydrothermal fluids deposited layers of chalcedony over extended periods, often trapped with iron oxides.

Uses & applications

Highly valued as a lapidary material for slicing, polishing, cabochons, jewelry making, and ornamental decorative specimens.

Geological facts

The distinctive orange and red coloration comes from hematite or goethite inclusions trapped inside the translucent chalcedony matrix.

Field identification & locations

Identified by its waxy texture, translucency when backlit, hardness (scratches glass), and characteristic banded or orbicular/botryoidal internal inclusions. Commonly found in gravel beds and volcanic terranes worldwide.

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Potassium Feldspar (Orthoclase)

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Mineral

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Mineral/Rock