Granite
Granite (a broadly defined plutonic igneous rock, often more specifically classified as quartz monzonite or granodiorite based on precise mineral percentages)
igneous
Category
Mineral (Specifically A Mineraloid)
Browse mineral (specifically a mineraloid) specimens identified by the Rock Identifier community.
Chert (specifically Yellow/Tan Chert)
Silicon Dioxide (SiO2)
sedimentary
Aragonite (variety 'Flos Ferri')
Aragonite (CaCO3)
Mineral
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
igneous
Chert (specifically Jasper/Flint pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Yellow/Honey Jasper variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Blue Chert or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Gray/Blue Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)
Metamorphic Rock
Mookaite Jasper
Siliceous (chert) sedimentary rock, a form of Jasper
Sedimentary
Chert (specifically Tan/Brown Chert)
Chert (SiO2)
sedimentary
Lace Agate (specifically Red Lace Agate)
Silicon Dioxide (SiO2) - variety of Chalcedony/Quartz
Mineral
Chert (specifically Gray/Black Chert)
Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)
sedimentary
Garnet Beads
Garnet Group (complex nesosilicates, e.g., Almandine Fe3Al2(SiO4)3)
Mineral
Unakite
Epidote-Feldspar rock
Metamorphic Rock
Emerald
Beryl (Be₃Al₂Si₆O₁₈), specifically the green variety colored by trace amounts of chromium or vanadium.
Mineral
Opalite
Synthetically produced glass (Silicon Dioxide with metallic inclusions)
Mineraloid (Man-made Glass)
Quartz (Milky Quartz)
Quartz (SiO2 - Silicon Dioxide)
Mineral
Amber
Succinite (fossilized tree resin)
mineraloid / sedimentary organic material
River/Stream Pebble
Clast / Detrital Grain / Rounded Sedimentary Particle (Compositionally variable, commonly Quartz, Feldspar, Chert, or other resistant rock fragments)
Mineral, specifically a rock fragment
Aventurine (likely Green Aventurine)
Silicon Dioxide (SiO2) with mineral inclusions
Mineral/Mineraloid within a rock matrix
Hypersthene (or Enstatite/Ferrosilite)
Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)
Mineral
Agate (or Banded Agate)
Agate (a variety of Chalcedony, which is a cryptocrystalline form of Quartz); Chemical Formula: SiO₂ (Silicon Dioxide)
Mineral, specifically a Cryptocrystalline Quartz variety
Amethyst
SiO2 (Silicon Dioxide)
Mineral
Marble
Metamorphosed Limestone/Dolomite
metamorphic
Tiger's Eye (specifically Blue/Golden mixed or Hawk's Eye)
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
BROWN GRANITE (likely 'Tan Brown' or similar)
Granite (specifically a variety rich in orthoclase feldspar, often with biotite and possibly hornblende)
igneous
Yellow Chalcedony (common opal or chert variant)
Silicon Dioxide (SiO2)
sedimentary (mineraloid/microcrystalline quartz)
Diamond
Carbon (C), specifically a solid form of the element carbon with atoms arranged in a crystal structure called diamond cubic.
Mineral
Goldstone (Synthetic Aventurescence Glass)
Cuprous Aventurescent Glass (Silicon Dioxide with Copper inclusions)
mineraloid / man-made material
Cullet Glass (Strawberry Glass)
Amorphous Silicon Dioxide (SiO2) with metallic dopants
Mineraloid (Synthetic/Man-made)
Labradorite
Labradorite (a variety of Plagioclase Feldspar), Na(AlSi3O8) to Ca(Al2Si2O8)
Mineral
Sunstone
Plagioclase Feldspar (specifically Oligoclase variety with hematite or goethite inclusions) Chemical Formula: (Ca,Na)(Al,Si)2Si2O8
Mineral
Sunstone
Plagioclase Feldspar (specifically Oligoclase variety containing hematite or goethite inclusions)", composition: (Ca,Na)(Al,Si)2Si2O8
Mineral
Tiger's Eye (specifically Blue Tiger's Eye / Falcon's Eye)
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
Chert or Flint (polished/water-worn)
Chert (a microcrystalline or cryptocrystalline variety of quartz, SiO2). Flint is a specific variety of chert.
Sedimentary (most likely, as Chert is a sedimentary rock often found as nodules in limestone or as bedded deposits; however, it can also form by metasomatic replacement, which leans towards metamorphic processes under certain conditions)
Mixed Chalcedony and Jasper Bracelet (possibly 'Ocean Jasper' or similar banded variety for brown beads, and blue/grey Chalcedony for the translucent beads)
Chalcedony (SiO2), Jasper (SiO2 with impurities)
Mineral (specifically a cryptocrystalline variety of Quartz)
Tiger's Eye
Tiger's Eye (a variety of Quartz, SiO₂)
Mineral (specifically a gemstone variety)
Quartz (likely) or a Quartzite Pebble
Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.
Mineral, specifically a detrital grain
Obsidian
Obsidian (volcanic glass)
Igneous
Jasper, possibly Brecciated Jasper or Ocean Jasper due to patterns and color
Silicon Dioxide (SiO2), a variety of Chalcedony
Sedimentary Rock
Green Aventurine (likely)
Silicon dioxide (SiO2) with fuchsitemica inclusions
Mineral (specifically a variety of Quartz)