Amethyst
Silicon Dioxide (SiO2) with iron impurities
Category
Browse mineral like byproduct (technogenic) specimens identified by the Rock Identifier community.
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Granite (Alkali-feldspar Granite)
Felsic Plutonic Rock (Primary minerals: Quartz SiO2, Orthoclase KAlSi3O8, Plagioclase (Na,Ca)AlSi3O8)
Green Schist
Greenschist (Chlorite Schist)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Gneiss
Gneiss (High-grade metamorphic rock)
Rose Quartz
Silicon Dioxide (SiO2)
Pink Sapphire (Corundum)
Aluminum Oxide (Al2O3) with Chromium/Iron impurities
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony replacing $SiO_2$)
Granite
Granite
Granatic Pegmatite
Pegmatitic Granite
Granitic Pegmatite
Pegmatite containing Quartz, Pink Potassium Feldspar, and Muscovite Mica
Diorite with Xenolith
Phaneritic Intermediate Plutonic Rock
Diorite (River Pebble)
Intermediate Phaneritic Igneous Rock
Schist (with Iron Oxide)
Mica Schist
Dendritic Opal
Hydrated Silica with Manganese inclusions (SiO2·nH2O)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Weathered Gabbro or Diorite (Igneous Cobble)
Phaneritic Basic/Intermediate Igneous Rock
Eudialyte
Na15Ca6Fe3Zr3Si26O72(OH,Cl)2 (Eudialyte Group)
Greenstone / Quartzite Pebble
Metamorphosed Quartz-rich Rock
Dendritic Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Mahogany Obsidian
Volcanic Glass (SiO2 + Fe2O3)
Diorite
Intermediate Phaneritic Igneous Rock
Amygdaloidal Basalt
Extrusive Igneous Rock with Amygdules
Petrified Wood
Silicified Wood (SiO2)
Sandstone
Sedimentary Rock (Quartz Sandstone)
Sandstone
Arenite (SiO2 primarily)
Biotite Schist
Biotite-rich Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)
Smoky Quartz
Silicon Dioxide (SiO2)
Limonite (Iron Ore)
Limonite (Hydrous iron(III) oxide-hydroxide mixture, FeO(OH)·nH2O)
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
White Chalcedony (likely Common Opal or Milky Quartz)
Silicon Dioxide (SiO2)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Malachite
Malachite (Copper Carbonate Hydroxide) - Cu2CO3(OH)2
Gemstone Tree Brooch (Agate and Quartz)
Silicon Dioxide (SiO2)
Quartz Geode
Crystalline Quartz (SiO2) within a sedimentary/igneous host
Specular Hematite
Hematite (Iron(III) oxide, Fe2O3)
Smoky Quartz
Smoky Quartz (Silicon Dioxide - SiO2)
Granite
Phaneritic intrusive igneous rock (approx. 70 percent SiO2)
Geode (Quartz)
Silicon Dioxide (SiO2)
Tumbled Quartz (Peach Quartz / Red Quartz)
Silicon Dioxide (SiO2)
Quartz with Inclusions
Silicon Dioxide (SiO2) with various mineral inclusions
Sandstone (Iron-stained)
Arenite (primarily SiO2 with Fe2O3 staining)