Sandstone (with banding/weathering)
Clastic Sedimentary Rock (primarily SiO2)
Category
Browse mineral, specifically a detrital grain specimens identified by the Rock Identifier community.
Sandstone (with banding/weathering)
Clastic Sedimentary Rock (primarily SiO2)
Silty Shale
Silty Shale (Fissile Sedimentary Rock)
Smoky Quartz (with complementary stones in jewelry setting)
Smoky Quartz (Silicon Dioxide - SiO2)
Smoky Quartz (with inclusions)
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2) with aluminum impurities
Ocean Jasper
Spherulitic Chalcedony (SiO2)
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
N/A (This is a digital image of a bar graph)
Digital Data Visualization (Bar Chart)
Sandstone (Banded)
Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide staining)
Peridot
Olivine (specifically, the gem-quality variety forsterite, (Mg,Fe)2SiO4)
Petrified Wood (Jet or Coalified Wood appearance)
Silicified wood (principally SiO2) or Carbonized Wood
Quartz (Float/Abraded)
Quartz (SiO₂)
Pearl
Calcium carbonate (CaCO3) + organic conchiolin (Biogenic Mineral)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with impurities of iron)
Ironstone Concretion (Iron-rich Mudstone)
Siderite / Geothite concretion (FeCO3 / FeO(OH))
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Sandstone Clast
Arenite (primarily SiO2)
Beach Agate (Chalcedony)
Silicon Dioxide (SiO2)
Agate with Quartz Druzy
Silicon Dioxide (SiO2) - Microcrystalline and Macrocrystalline varieties
Kyanite in Quartz
Kyanite (Al2SiO5) with Quartz (SiO2)
Petrified Wood
Silicified Wood / Chalcedony (SiO2)
Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
Amazonite
Potassium Feldspar (KAlSi3O8)
Sandstone Concretion with Quartz Center
Sedimentary Clastic Rock (SiO2 matrix with Quartz core)
Ocean Jasper
Orbicular Jasper (variety of Chalcedony/Quartz, SiO2)
Amazonite
Potassium Feldspar (KAlSi3O8) with lead impurities
Marble
Recrystallized Calcite (CaCO3)
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
Pink Granite
Granite (Felsic Plutonic Rock)
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Ruby (Raw/Rough)
Corundum (Al2O3 with Chromium trace)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)
Sandstone (Banded)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
Orca Agate
Chalcedony (Microcrystalline Quartz, SiO2)
Chalcedony (Botryoidal Agate vein)
Chalcedony (Microcrystalline Quartz) - SiO2
Jasper (Petrified Wood variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Smoky Quartz on Feldspar (Granite Pegmatite)
Silicon Dioxide (SiO2) with Potassium Aluminum Silicate (KAlSi3O8)
Greywacke (River Slikenside)
Greywacke (Lithic Sandstone)
Moss Agate
Silicon Dioxide (SiO2) with inclusions
Banded Sandstone (Wonderstone)
Sandstone with Liesegang Rings (SiO2 with Iron Oxides)