mineral

Druzy Quartz on Host Rock

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale. Color: Clear to milky white/tan with reddish iron staining. Luster: Vitreous (glassy) on crystal faces, earthy on the host matrix. Crystal structure: Hexagonal/Trigonal (tiny pyramidal points). Cleavage: None (conchoidal fracture).

Hardness: 7 on the Mohs scale
Color: Clear to milky white/tan with reddish iron staining

Identified March 19, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal precipitation where silica-rich fluids permeate cavities or fractures in a host rock (likely limestone or volcanic tuff). As the fluid cools or evaporates, tiny crystals grow on the surface. These specimens can range from millions to hundreds of millions of years old depending on the regional geology.

Uses & applications

Used primarily in lapidary work for jewelry (beads and pendants) and as decorative display specimens for mineral collectors. Some industrial quartz is used in glassmaking and electronics, though crystalline clusters like this are valued for aesthetics.

Geological facts

The term 'druzy' (or drusy) refers to a coating of fine crystals on a rock surface that resembles sugar or glitter. Large druzy clusters are often found inside geodes or lining vugs in mineral veins.

Field identification & locations

Identify in the field by the 'glitter' effect when rotated in sunlight and its extreme hardness; quartz will easily scratch glass. Look for it in areas with high limestone concentrations or volcanic activity. Commonly found in locations like the Midwestern US (Missouri/Iowa), Brazil, and Morocco.