mineral

Quartz Geode or Nodular Quartz

Silicon Dioxide (SiO2) in Host Matrix

AI-generated identification · may be incorrect

Hardness: 7 on Mohs scale; Color: translucent white to tan; Luster: Vitreous/Glassy; Crystal Structure: Trigonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: translucent white to tan
Luster: Vitreous/Glassy

Identified May 24, 2026More mineral →

Explore Quartz Geode or Nodular Quartz in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 7 on Mohs scale; Color: translucent white to tan; Luster: Vitreous/Glassy; Crystal Structure: Trigonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed by mineral-rich hydrothermal fluids filling cavities or bubbles in volcanic or sedimentary host rock. As the water evaporates or cools, silica precipitates out, slowly growing crystals inward.

Uses & applications

Primarily used for collecting, decorative display, holistic practices, and educational purposes. Pure quartz is used in glassmaking and electronics.

Geological facts

Quartz is the second most abundant mineral in Earth's crust. Geodes are essentially time capsules that can take millions of years to grow their internal crystals.

Field identification & locations

Identify in the field by looking for rounded, knobby stones that feel lighter than they look (if hollow) or show translucent glassy patches compared to the dull crust. Commonly found in desert regions or dry riverbeds.