Quartz Geode (Nodule)
Silicon Dioxide (SiO2)
Category
Browse sedimentary and igneous specimens identified by the Rock Identifier community.
Quartz Geode (Nodule)
Silicon Dioxide (SiO2)
Jasper and Basalt Mix (Dark Chert/Basalt River Pebble)
Silicon Dioxide (SiO2) or Mafic extrusive igneous rock
Fluorite Bracelet (light green beads) and possibly Lavender Jadeite (purple bead)
Fluorite: CaF₂ (Calcium Fluoride); Jadeite: NaAlSi₂O₆ (Sodium Aluminum Silicate)
Rounded gray pebble, likely limestone or fine-grained basalt
Indeterminate from image; possible micritic limestone (calcite, CaCO₃) or basalt (plagioclase, pyroxene, minor oxides)
River Pebble (Greywacke or Basaltic)
Massive Greywacke or Basaltic Andesite
Crushed Stone (Likely Limestone or Granite)
Calcium Carbonate (CaCO3) for Limestone / Quartz and Feldspar for Granite
Painted River Pebble (likely Basalt or Greywacke)
Aphanitic Lithic Clast with Anthropogenic Pigment coating
River Rock
Various, often Sandstone, Basalt, or Granite
Metal Chain (Likely Steel or a Steel Alloy)
Steel (primarily iron and carbon); specific alloy unknown
Jasper and Basalt (Mixed Breccia or Chert)
Silicon Dioxide (SiO2) with Ferromagnesian silicates
Crushed Stone (Gravel/Aggregates)
Crushed rock aggregate (varied composition including Granite, Limestone, and Quartz)
Quartz Geode/Druzy Quartz
Quartz (SiO₂)
Gravel or Crushed Stone
Fragmented Aggregate Stone
River Rock (Glacial Cobbles)
Fluvial Alluvium (Mixed lithology including Quartzite, Basalt, and Granite)
River Pebbles (Stream-rounded rocks)
Fluvial Detritus (varied mineralogy)
Native American Hammerstone / Pitted Stone
Modified lithic artifact (often quartzite, basalt, or granite)
Quartz Geode
Silicon Dioxide (SiO2) in a Geode body
Jasper (specifically Polychrome or Desert Jasper)
Silicon Dioxide (SiO2) with impurities
Quartz Geode (with Agate banding)
Silicon Dioxide (SiO2)
Tumbled clear quartz
Quartz (SiO₂)
Epidote (or Epidote-rich rock)
Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).
Tumbled white quartz (likely milky quartz)
Quartz, silicon dioxide (SiO₂)
Mixed small mineral specimens, likely quartz varieties
Uncertain from the image; translucent pieces may be quartz (SiO₂), while golden-brown pieces could be iron-stained quartz or calcite
Pyrite
Iron Sulfide (FeS2)
Tumbled milky quartz
Quartz, SiO₂; trigonal crystal system
Quartz (likely milky or iron-stained quartz)
Quartz, silicon dioxide (SiO₂)
Milky quartz cluster
Quartz (silicon dioxide, SiO₂)
Tumbled milky quartz
Quartz (silicon dioxide, SiO₂)
Milky quartz crystal cluster
Quartz (silicon dioxide, SiO₂)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Likely milky quartz
Quartz (silicon dioxide, SiO₂)
Clear quartz crystal pendant
Quartz (silicon dioxide, SiO₂)
Magnetite / Ironstone
Magnetite (Fe3O4)
Clear quartz (rock crystal)
Quartz, crystalline silicon dioxide (SiO₂)
Red coral (coral beads)
Precious coral, usually Corallium spp.; composed primarily of calcium carbonate (calcite)
Milky quartz
Quartz (silicon dioxide, SiO₂)
Apatite
Fluorapatite (Ca5(PO4)3F)
Quartz Sand Grain
Silicon dioxide (SiO2)
Tumbled clear quartz
Quartz (silicon dioxide, SiO₂)
Small quartz-rich mineral fragment
Quartz (SiO₂), possibly milky or chalcedonic quartz
Quartz
Silicon dioxide (SiO2)
Dalmatian Jasper
Aplite with Arfvedsonite inclusions