mineral

Quartz (Agate/Chalcedony)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent grey/brown (smoky) with internal inclusions; Luster: Vitreous to waxy; Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture.

Hardness: 7 on Mohs scale
Color: Translucent grey/brown (smoky) with internal inclusions
Luster: Vitreous to waxy

Identified June 19, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Translucent grey/brown (smoky) with internal inclusions; Luster: Vitreous to waxy; Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture.

Formation & geological history

Formed from the deposition of silica-rich groundwater in cavities of volcanic or sedimentary rocks. It is a crypto-crystalline variety of quartz that develops over millions of years.

Uses & applications

Used in jewelry (cabochons), as an abrasive in industrial applications, in watchmaking, and for metaphysical stone collection.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. This specific piece shows a waxy luster typical of chalcedony and has internal fractures or inclusions that can occasionally form patterns.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and smooth, curved conchoidal fractures. Commonly found in riverbeds, volcanic regions, and desert pavements.