Obsidian
Volcanic glass (SiO2 - Silicon Dioxide)
Category
Browse mineral like byproduct specimens identified by the Rock Identifier community.
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide)
Gneiss
Gneiss
Greenschist
Chlorite schist
Carved Mottled Greenish-Yellow Crystal/Glass Object
Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.
Fossil Shell (Bivalve)
Class Bivalvia (fossilized)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Granitic Pegmatite (with Smoky Quartz and Mica)
Granitic Pegmatite (composed of SiO2, KAl2(AlSi3O10)(OH)2, and (K,Na)(AlSi3O8))
Geode (Unopened)
Silica-rich Concretion (primarily SiO2)
Greenstone / Greenschist
Greenschist facies metamorphic rock (composed primarily of chlorite, actinolite, and epidote)
Quartz-veined Metamorphic Rock
Quartz-veined Schist or Gneiss
Quartz-veined Basalt or Limestone Pebble
Quartz vein in host rock (Silicate mineral in carbonate or volcanic matrix)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Quartz and Iron Oxide
Quartz (Silicon Dioxide, SiO2) with possible Limonite/Hematite inclusions
Schist
Mica Schist
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Granite
Intrusive Igneous Rock
Gneiss
Gneiss
Diorite
Diorite
Banded Gneiss
Gneiss (Metamorphic Rock)
Gneiss
Gneiss (Foliated Metamorphic Rock)
Chalcedony on Matrix
Silicon Dioxide (SiO2)
Dendritic Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
Botryoidal Chalcedony (Druzy Quartz)
Silicon Dioxide (SiO2)
Chalcedony (Common Opal or Agate variant)
Silicon Dioxide (SiO₂)
Agate (specifically a Thunderegg/Agate Nodule)
Cryptocrystalline Quartz (SiO2)
Obsidian
Obsidian (principally SiO2 + MgO, Fe3O4)
Sandstone (likely Arkosic)
Clastic Sedimentary Rock
Sandstone (likely Arkosic or Quartzose)
Sandstone (SiO2 dominated)
Quartz Geode
Crystalline Silicon Dioxide (SiO2) in a Geodic structure
Quartz with Schist Matrix
Crystalline Silicon Dioxide (SiO2) in micaceous schist
Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
Chrysocolla
Hydrated copper silicate - Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O
Gold Sheen Obsidian
Volcanic Glass (SiO2 + Fe3O4 / Gas Inclusions)
Black Obsidian
Volcanic Glass (SiO2)
Diamond
Native Carbon (C)
Smoky Quartz
Silicon Dioxide (SiO2)
Amethyst Geode
Amethyst (Silicon Dioxide, SiO2 with iron impurities)
Chalcedony with Druzy Quartz
Silicon Dioxide (SiO2)
Agate
Silicon dioxide (SiO2)
Emerald / Green Beryl
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
Quartz (Smoky or Clear variety with inclusions)
Silicon Dioxide (SiO2)
Geode (Unopened)
Chalcedony Geode (Hydrated Silicon Dioxide, SiO2)