mineral

Botryoidal Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to light tan; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal (microcrystalline); Cleavage: None; Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to light tan
Luster: Vitreous to waxy

Identified June 9, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to light tan; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal (microcrystalline); Cleavage: None; Specific gravity: 2.65.

Formation & geological history

Formed through the precipitation of silica-rich hydrothermal fluids in cavities or fractures within host rocks. The rounded, grape-like structure occurs when minerals grow around many nuclei simultaneously at a rapid rate.

Uses & applications

Primarily used as a decorative collector's specimen. Quartz in general is used in electronics (oscillators), glassmaking, and as an abrasive in industry.

Geological facts

The term 'botryoidal' is derived from the Greek word 'botrys', which means a bunch of grapes. While unusual for quartz, this habit is common in minerals like hematite and malachite.

Field identification & locations

Identify by its characteristic 'bumpy' or grape-cluster surface and its high hardness (it will easily scratch glass). Common in volcanic regions and sedimentary geodes.