Pet Rock (Man-made Quartzite or Granite Cobble)
Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica
igneous or metamorphic (base stone); anthropogenic (decoration)
Category
Metamorphic (Likely Gneiss Or Schist Based On Texture)
Browse metamorphic (likely gneiss or schist based on texture) specimens identified by the Rock Identifier community.
Coquina
Bioclastic Limestone
sedimentary
Basalt
Basalt (Mafic volcanic rock)
igneous
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)
metamorphic
Obsidian (likely Golden Sheen Obsidian or Rainbow Obsidian, given the subtle sheen visible on some beads)
Obsidian (volcanic glass, predominantly SiO2 with various impurities)
Igneous
Green Aventurine
Quartz (SiO2) containing Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
metamorphic
Quartzite
Quartzite (Primary mineral: SiO2)
metamorphic
Eclogite
Eclogite (composed primarily of Omphacite and Pyrope Garnet)
metamorphic
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Quartz (Water-worn pebble)
Silicon Dioxide (SiO2)
mineral
Quartzite and Jasper Pebbles
Quartzite (re-crystallized Quartz) and Cryptocrystalline Quartz (SiO2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Greisen
Greisen
Metamorphic
Basalt
Mafic Volcanic Rock (primarily Plagioclase and Pyroxene)
Igneous
Fluorite with Rhodochrosite
Fluorite (CaF2) and Rhodochrosite (MnCO3)
Mineral
Rutilated Quartz (likely Citrine or Smoky Quartz with Rutile inclusions)
SiO2 with TiO2 inclusions (Quartz with Rutile)
Mineral
Porphyritic Basalt
Porphyritic Basalt (with plagioclase phenocrysts)
igneous
Quartzite
Quartzite (SiO2)
metamorphic
Unakite (Epidotized Granite)
Unakite (Rock composed of Epidote Ca2(Al,Fe)3(SiO4)3(OH), Orthoclase KAlSi3O8, and Quartz SiO2)
metamorphic
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
Quartzite (River Cobble)
Metamorphosed Quartz Sandstone (SiO2)
metamorphic
Orange Quartzite (Tumbled Beach Pebble)
Quartzite (primarily SiO2)
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Amazonite
KAlSi3O8 (Potassium Aluminum Silicate)
mineral
Basalt with Vesicular Texture (Beach Cobble)
Vesicular Basalt (Aphanitic Igneous Rock)
igneous
Quartzite
Quartzite (SiO2)
metamorphic
Banded Agate
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)
N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)
Organic (if resin) or Synthetic (if glass); simulating Sedimentary or Metamorphic (for natural stones)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide / Chalcedony)
metamorphic
Petrified Wood
Silicified wood (primarily Quartz/Chalcedony, SiO2)
metamorphic
Greenstone (Greenstone River Pebble)
Greenschist (metamorphosed mafic igneous rock)
metamorphic
Lavender Jade (Jadeite)
Jadeite - Sodium Aluminum Silicate (NaAlSi2O6)
metamorphic
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
metamorphic
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Basalt
Basalt (Aphanitic Mafic Volcanic Rock)
igneous
Quartzite
Quartzite (Primary mineral: SiO2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Basalt
Basalt (Aphanitic Mafic Volcanic Rock)
igneous
Granite
Granite (a felsic intrusive igneous rock)
igneous
Coarse Sand Grain / Lithic Fragment
Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)
sedimentary
Petrified Wood
Silicified wood (Quartz, SiO2)
metamorphic