mineral

Likely druzy quartz/agate specimen

Quartz (SiO₂), possibly iron-stained chalcedony or agate

AI-generated identification · may be incorrect

Brown to reddish-brown, translucent to opaque nodules with sparkling drusy crystal surfaces; quartz hardness 7, vitreous luster, hexagonal crystal structure, no cleavage, and specific gravity about 2.65. The pale host may be quartz, calcite, or a light-colored matrix mineral.

Identified August 22, 2026More mineral →

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Physical properties

Formation & geological history

Likely formed when silica-rich groundwater filled cavities or fractures in volcanic rock, depositing chalcedony followed by tiny quartz crystals; iron oxides produced the brown-red coloration. Exact geological age and locality cannot be determined from the image.

Uses & applications

Used as lapidary material, cabochons, polished specimens, and decorative stone; quality depends on crystal sparkle, color, pattern, and completeness.

Geological facts

Drusy quartz consists of thousands of microscopic quartz crystals coating a surface. Red-brown coloration commonly reflects hematite or goethite inclusions.

Field identification & locations

Identify by testing for quartz-like hardness, glassy sparkle, conchoidal fracture, and lack of cleavage; avoid scratching with steel unless appropriate. Common sources include Brazil, Uruguay, Mexico, Morocco, and the United States.