Granite
Phaneritic Felsic Igneous Rock (primarily Quartz, Alkali Feldspar, and Plagioclase)
Category
Browse synthetic polymer (synthetic material) specimens identified by the Rock Identifier community.
Granite
Phaneritic Felsic Igneous Rock (primarily Quartz, Alkali Feldspar, and Plagioclase)
Olivine in Basalt matrix
Peridotite (Mg, Fe)2SiO4
Basalt (River Pebble)
Basalt
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Milky Quartz (Water-worn pebble)
Quartz (Silicon Dioxide, SiO2)
Sandstone
Arenite (primarily SiO2 with various cementing agents)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Vesicular Basalt (Iron-rich)
Scoriaceous Basalt / Oxidized Vesicular Basalt
Sandstone (likely Quartzose)
Arenite (primarily SiO2)
Amazonite
Microcline (K(AlSi3O8))
Jasper
Silicon dioxide (SiO2) with impurities
Red Sandstone
Arenite (Fe2O3-rich)
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Hematite inclusions
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
Chlorastrolite (Isle Royale Greenstone)
Chlorastrolite (Pumpellyite-(Mg,Fe2+): Ca2MgAl2(Si2O7)(SiO4)(OH)2∙H2O)
Bivalve Fossil (Clam/Mollusk)
Class: Bivalvia (Order: Veneroida), Calcium Carbonate (CaCO3)
Chert (Gravel pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Snakeskin Agate
Agate (Cryptocrystalline Quartz, SiO2)
Snowflake Obsidian
Volcanic glass containing Spherulitic Cristobalite (SiO2)
Ferruginous Slag (Iron Smelting Byproduct)
Fused Silicate Scoria (Amorphous mixture of FeO, SiO2, and CaO)
Moss Agate
Silicon Dioxide (SiO2) with Manganese or Iron Oxide inclusions
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
River Stone (River Pebbles)
Alluvial Deposit (typically Quartzite, Sandstone, or Granite clasts)
Fossilized Bone Fragment
Permineralized Vertebrate Fossil (Hydroxyapatite replaced by Minerals)
Fossil Coral (Rugose Coral Fragment)
Rugosa (extinct order of solitary and colonial corals)
Rough Diamond
Diamond (C)
Quartzite (River Cobble)
Metamorphosed Quartz Sandstone (SiO2)
Chert (and Flint)
Silicon dioxide (SiO2) - Microcrystalline quartz
Tiger's Eye (Multicolor/Variegated)
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxides)
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
Banded River Cobble with Mafic Dike
Hydrothermally altered Graywacke or Sandstone with Mafic Intrusion
Yellow Jasper
Silicon Dioxide (SiO₂)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Limonite (Iron Ore)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
Yellow Ocher (Limonite)
Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O
Slag (Industrial Glass)
Anthropogenic Amorphous Vitreous Silicate
Chert (Jasper nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Titanium Aura Quartz (Aura Quartz)
Titanium-coated Silicon Dioxide (SiO2)
Chert (Cherty Shale / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (specifically Yellow/Honey Jasper variety)
Cryptocrystalline Quartz (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Fossil Shell (Bivalve)
Phylum Mollusca, Class Bivalvia (typically composed of Calcium Carbonate / CaCO3)