Quartz with Inclusions

Physical Properties

Hardness: 7 on Mohs scale; Color: Variable (semi-translucent with dark inclusions); Luster: Vitreous to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & Geological History

Formed through the cooling of silica-rich magma or from hydrothermal veins. The inclusions (likely graphite, tourmaline, or chlorite) were trapped within the quartz lattice during crystallization.

Uses & Applications

Used primarily for decorative purposes, crystal collecting, jewelry-making (tumbled stones), and as a minor gemstone specimen.

Geological Facts

Quartz is one of the most abundant minerals on Earth. When and if the inclusions are dark and needle-like, it is often referred to locally as 'rutilated' or 'tourmalinated' quartz, though this specimen appears more like a beach-worn cobble with concentrated dark matrix.

Field Identification & Locations

Identify by its ability to scratch glass and lack of cleavage. Commonly found in riverbeds, beaches, and mountainous regions worldwide. Look for the translucent quality compared to surrounding opaque rocks.

Identified on: 5/3/2026

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