Quartz
Silicon Dioxide (SiO2)
Category
Browse mineral in igneous rock specimens identified by the Rock Identifier community.
Quartz
Silicon Dioxide (SiO2)
Porphyry (Flower Stone)
Porphyry (Andesite or Basalt matrix)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Amygdaloidal Basalt
Amygdaloidal Basalt (Host rock) with Quartz or Calcite amygdules
Gneiss (Metamorphic Rock)
Gneiss
Rose Quartz
Silicon dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Pyrite in Matrix (likely Quartz or Schist matrix)
Iron Sulfide (FeS2)
Quartz (Milky or Cloudy Quartz)
Silicon Dioxide (SiO2)
Basalt River Pebble
Basalt (Aphanitic Mafic Volcanic Rock)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Note: No specimen visible
Orthoclase Feldspar
Potassium Feldspar (KAlSi3O8)
Sandstone
Quartz Sandstone (predominantly)
Quartz (Milky or Druzy Quartz)
Silicon Dioxide (SiO2)
Granodiorite
Phaneritic intrusive igneous rock (Granodiorite)
Pebble (likely Quartz or Chert)
SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.
Pyrite (on Quartz matrix)
Iron Disulfide (FeS2)
Fluorite (Green Fluorite)
Calcium Fluoride (CaF2)
Pyrite
Iron Sulfide (FeS2)
Granite
Phaneritic Plutonic Rock (High Silica content)
Quartz / Iron-Stained Quartz
Silicon Dioxide (SiO2) with iron oxide inclusions/staining
Banded Gneiss (with possible weathered sulfide or iron staining)
Gneiss, potentially with iron oxide/hydroxide staining (e.g., limonite) or weathered sulfides
Pink Granite
Phaneritic Felsic Igneous Rock (Rich in K-Feldspar)
Yellow Quartz (Citrine Quartz or Yellow Jasper)
Silicon Dioxide (SiO2) with iron impurities
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Banded Gneiss
Gneiss (variable mineral composition)
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Quartz (Smoky/Grey Variety)
Silicon Dioxide (SiO2)
Pink Granite
Granite (Phaneritic Acid Igneous Rock)
Potassium Feldspar (Orthoclase)
KAlSi3O8 (Potassium Aluminum Silicate)
Quartz (likely a weathered/tumbled piece)
Quartz (SiO₂)
Basalt River Stone
Basalt
Clear Quartz Crystal Cluster
Silicon Dioxide (SiO2)
Yellow Quartz (or Citrine Quartz)
Silicon Dioxide (SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Basalt
Mafic volcanic rock, primarily composed of Plagioclase, Pyroxene, and Olivine
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Magnetite
Magnetite (Fe3O4)
Pumice
Vesicular Rhyolite (highly vesicular igneous volcanic rock)
Unakite
Unakite (Epidotized Granite)
Sandstone
Sandstone (clastic sedimentary rock)