sedimentary
Quartz Geode in Sedimentary Host Rock
Silicon Dioxide (SiO2) in Carbonate Matrix
Hardness: 7 (Quartz) / 3 (Limestone), Color: Colorless to brownish-tan crystals, Luster: Vitreous to dull, Crystal Structure: Trigonal/Hexagonal crystals, Cleavage: None
Identified More sedimentary →
Explore Quartz Geode in Sedimentary Host Rock in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Quartz) / 3 (Limestone), Color: Colorless to brownish-tan crystals, Luster: Vitreous to dull, Crystal Structure: Trigonal/Hexagonal crystals, Cleavage: None
Formation & geological history
Formed as secondary mineral precipitates within cavities (vugs) of sedimentary rocks, often limestone or dolostone, through groundwater deposition. Likely Paleozoic in age.
Uses & applications
Primarily for geological collecting, educational purposes, and decorative display.
Geological facts
This specimen shows a 'vug,' which is a small cavity in a rock lined with crystals. These are mini-geodes that haven't fully enclosed.
Field identification & locations
Identify by the contrast between the fine-grained matrix and the distinct crystalline growth inside the pocket; can be tested with a drop of vinegar (the matrix will fizz if it is limestone).
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Mudstone
Argillite / Siliciclastic sedimentary rock
sedimentary
Brown Sandstone (River Rock)
Arenite
sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary