Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
Category
Browse mineral in a matrix (likely quartz or feldspar) specimens identified by the Rock Identifier community.
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
Greisen
Greisen
Granite
Phaneritic Igneous Rock (Granitic)
Conglomerate
Conglomerate (SiO2 matrix with various silicate clasts)
Chert (Jasper/Limonitic Chert)
Microcrystalline Quartz (SiO2)
Clear Quartz crystals on a Matrix base (Geode fragment)
Silicon Dioxide (SiO2)
Quartz (River Pebble)
Quartz (Silicon Dioxide, SiO2)
Quartz (likely) or a Quartzite Pebble
Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.
Quartz
Silicon Dioxide (SiO₂)
Diorite
Diorite (intermediate intrusive igneous rock)
Red Porphyry
Porphyritic Andesite or Rhyolite
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Granitic Gneiss
Gneiss (Polymetamorphic Granitic Gneiss)
Unakite / Epidosite
Epidote with Orthoclase and Quartz; (Ca2(Al2,Fe)(SiO4)3(OH)) / (KAlSi3O8) / (SiO2)
Quartzite
Quartzite (primarily SiO2)
Sandstone (specifically Arkose or Quartz Arenite)
Arenite (primarily SiO2 with possible Feldspar)
Graphite-veined Quartzite
Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)
Diorite
Diorite
Granite
Granite (Main minerals: Quartz SiO2, Feldspar KAlSi3O8, Mica)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Yellow Quartz / Quartzite Pebble
Silicon Dioxide (SiO2)
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
Red Quartzite
SiO2 (Silicon Dioxide with iron oxide impurities)
Rose Quartz with Feldspar Inclusions
Silicon Dioxide (SiO2)
Milky Quartz (Gold-bearing Prospecting Specimen)
Silicon Dioxide (SiO2)
Yellow Chalcedony (Agate Pebble)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Garnet Schist
Almandine Garnet in Mica Schist (Fe3Al2(SiO4)3)
Clear Quartz (or Rock Crystal)
Quartz (SiO₂)
Fossiliferous Limestone
Calcite (CaCO3) Rich Bio-sedimentary Rock
Conglomerate
Clastic Sedimentary (Conglomerate)
Chert Pebble (Yellow Jasper)
Microcrystalline Quartz (SiO2)
Green Aventurine
Quartzite with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
Granite
Phaneritic Felsic Igneous Rock (Granite)
Quartzite with Quartz Veining
Quartzite (primarily SiO2)
Granodiorite
Granodiorite (containing Plagioclase, Quartz, and K-feldspar)
Raw Citrine
Citrine (Silicon Dioxide - SiO2)
Granite (River-worn Cobble)
Phaneritic Felsic Igneous Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Granite
Phaneritic Granitoid (Primary minerals: Quartz SiO2, Feldspar KAlSi3O8, and Biotite/Mica)
Quartz (specifically a water-worn river pebble)
Silicon Dioxide (SiO2)
Granite
Phaneritic Felsic Igneous Rock
Granite
Granite (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)